ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • International Union of Crystallography  (2,491)
  • International Union of Crystallography (IUCr)  (2,491)
  • American Meteorological Society
  • 1995-1999
  • 1980-1984  (3,533)
  • 1975-1979  (3,096)
  • 1980  (3,533)
  • 1975  (3,096)
Collection
Years
  • 1995-1999
  • 1980-1984  (3,533)
  • 1975-1979  (3,096)
Year
  • 1
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 29-36 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A stereographic projection method of analysis has been developed for analyzing the misorientation contrast of crystal subgrain boundaries which are observed in Berg–Barrett X-ray micrographs. The boundary appearance is described in terms of the geometry of the boundary with respect to the crystal surface, the angular misorientation of the adjacent subgrains, and the X-ray diffraction conditions. The rotation axis for the misorientation of adjacent subgrains, including the sense of the rotation, and the amount of misorientation is determined from the width and relative contrast of the boundary in various images. Experimental results are described for subgrain boundaries in zinc crystals solidified along different crystallographic growth directions. The Burgers vectors of the dislocations composing the subgrain boundary are indirectly determined by this method.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 42-44 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A means of measuring strain and lattice parameter directly in epitaxic layers by `double-crystal' X-ray diffraction is presented. The method described has three major advantages; that it is achieved by a simple addition to a commercial goniometer; that the area of sample illuminated is defined solely by the collimator; and that single or double-crystal diffraction can be selected, simultaneously if needed, on exactly the same specimen area.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 45-48 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A silicon powder Standard Reference Material, SRM-640, has been prepared for use as a standard in powder diffractometry. Powder diffraction measurements were performed with a tungsten internal standard and a high-angle goniometer. The measured a/λ is 3.525176. With λ(Cu Kα1 peak) taken as 1.5405981 Å, a = 5.430880 (35) Å, uncorrected for refraction. Comparison of a with values obtained with a single-crystal from one of the boules reveals a difference of 3 parts in 105. This difference suggests a subtle systematic error in powder diffractometry or a change in lattice spacing near crystal boundaries. Use of the SRM should permit individual measurements of lattice parameters to be made reproducible to near 1 part in 105 and an absolute accuracy of at least 3 parts in 105.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 111-114 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The assumptions in the Borie & Sparks [Acta Cryst. (1971). A27, 198–201] procedure for the separation of order- and displacement-dependent components of diffuse X-ray scattering from a binary system AB are examined with the use of the concentration deviation (spin-like) notation. The more limiting assumption, that the structure-factor ratio η = (mAfA + mBfB)/(fA−fB) is constant in reciprocal space, is shown to produce an incomplete separation for normal variations in η. A matrix-inversion method for completing the separation is suggested for those cases in which the approximate equality of the Debye–Waller factors (DWF) of the individual atomic species indicates that some terms of the scattering equation may be neglected. The extension suggested by Ramesh & Ramaseshan [Acta Cryst. (1971). A27, 569–572] that anomalous dispersion induced changes in η could be used to separate the atomic static displacement properties of the various atomic pairs is shown to require a change in η greater than the variation of η across the reciprocal-space volume. Some difficulties of obtaining such a change are pointed out.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 121-126 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The role of positional information in determining the thermodynamics of crystalline solid solutions is considered. It is noted that, with certain exceptions (e.g.b.c.c. Fe–B), such solutions can be classified as being exclusively either substitutional or interstitial with respect to each solute. Calculation of thermodynamic properties of intersitital solutions requires knowledge of the types of sites preferentially occupied by the solute. The problem of determining that occupancy is considered for several binary systems. A cumulant expansion technique, which meets with good success in describing dilute, high-temperature, interstitial solutions, is applied to the case of high-temperature binary substitutional systems of similar metals. The technique is shown to be of limited utility in this application.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 127-127 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: It may be essential in certain cases (e.g. non-dilute alloys and dislocations) to take into account the (pair and higher-order) correlations in the defect distribution. To this end the kinematic expression for the total scattered intensity is rewritten.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 132-132 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: If the occurrence of one or two-dimensional local order in alloys or in neutron-irradiated materials has been known for many years, the observation by X-ray and neutron scattering of quasi-one-dimensional order due to displacements or correlated motions of atoms along independent chains is more recent. Examples to be discussed are given.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 75-75 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 76-76 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 128-128 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Structural studies showed that oxygen atoms in Ih ice are well ordered whereas hydrogen atoms are `statistically' distributed on two possible sites on each O–H–O bond.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 185-185 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The integral Huang diffuse X-ray scattering from crystals containing small dislocation loops can be analyzed to obtain two types of information: (1) the size distribution of the loops and (2) the total number of point defects contained in the loops. This technique has been applied to copper crystals irradiated under a number of conditions of neutron irradiation flux, dose and temperature, for which loops are produced, and to selected annealing studies of these loops, with all X-ray measurements made at room temperature.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 191-192 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Explanations for the broadening of X-ray line profiles of plastically deformed crystals in terms of the density and the distribution of the dislocations introduced during deformation are given.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 140-140 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The ω phase transformation in Zr–Nb alloys has been studied by measuring the X-ray diffuse scattering in the (110) plane and the Mössbauer diffuse scattering along the 〈111〉 direction of separate single crystals with compositions ranging from 8 to 30% Nb.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 141-141 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A simple crystallographic approach in obtaining the final martensitic structure [3R, 1R, 2H) from the initial displacive modes is presented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 142-142 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The theory of the diffuse scattering from crystals with small concentrations of point defects and small clusters is reviewed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 143-143 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Analytic expressions for the dilation and the stress tensor in reciprocal space are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 203-203 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The boundary between the −X and Z growth regions in synthetic quartz has been studied using X-ray topography and other techniques and it has been found that the crystal lattice remains coherent at the boundary.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 204-204 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The diffraction of electrons is, in principle, a very sensitive probe of the relative atomic positions in ordered or disordered crystals. The full potential of electron diffraction and electron microscopy methods for the study of local atomic arrangements has not been realised because of the difficulties of conducting experiments under sufficiently well defined conditions and because of the complications introduced by the dynamical diffraction processes involved.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 183-183 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The diffuse elastic neutron scattering due to distortion of the Pb host lattice around Bi substitutional atoms has been measured at the HFR in Grenoble and the results discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 175-183 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: For interstitials the scattering cross section between the Bragg reflections is very sensitive to the position of the defect atom and the displacements of the neighbouring lattice atoms. In contrast to this the scattering near the Bragg reflections (Huang scattering) is mainly governed by the displacement field at large distances from the defect and gives information about defect symmetry and strength [Trinkaus, H. (1972). Phys. Stat. Sol. (b) 51, 307–319]. For determining structures of point defects a measurement of scattering far from reciprocal-lattice points is therefore the best suited and most direct method. X-ray measurements of point-defect scattering in this region far from reciprocal-lattice points are difficult. With conventional X-ray set-ups it is not possible to separate the defect scattering from the thermal diffuse and Compton background scattering which is up to two orders of magnitude larger in the case of typical defect concentrations of some 10−4. Such measurements, however, become possible if large X-ray sources of high luminous density are used in connexion with multidetector arrangements. As an example an experimental arrangement [Haubold, H.-G. & Schilling, W. (1975). To be published; Haubold, H.-G. (1974). Rep. Kernforschungsanlage Jülich, JUL-1090-FF] is reviewed, in which the scattering cross-section of self-interstitials in aluminium was measured in samples containing an atomic density of interstitials up to 5 × 10−4.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 184-184 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Second-order pseudopotential calculations are known to reproduce fairly well the structure and phonon spectra of many simple metals. The validity of the underlying assumption of linear screening for impurities with valences and core radii close to those of the host can be checked a posteriori and by comparing calculated properties with measurements on dilute alloys, and, especially, coherent elastic neutron scattering.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 185-185 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Analytical methods to describe the scattering from crystals containing defect clusters with strong displacement fields are reviewed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 193-194 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Work which has been started at Pelindaba on small-angle scattering in neutron irradiated copper is described.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 193-193 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Voids formed in neutron irradiated metals are faceted on various crystallographic planes. This faceting has been shown to cause significant anisotropy in the small-angle scattering pattern. It is shown that it is possible to obtain the specific void surface energies from small-angle diffuse scattering data.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 224-224 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The weak-beam method of electron microscopy provides a means for studying lattice defects with greatly increased resolution compared with normal diffraction contrast techniques.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 386-387 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The thermal expansion of cyclopentadienylthallium, TlC5H5, was determined in the range 78 to 295 K, using X-ray powder diffractometry. Expansion is very anisotropic: α1 = 125 ± 12, α2 = 97 ± 5, α3 = 0 ± 4 (all 10−6 K−1). Directions and ratio of the two greatest expansion coefficients: α1 and α2, are explained by considering the shortest distances Tl+–Tl|+ in this ionic structure.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 392-395 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Several guanidinium salts have been studied since, because they contain six hydrogen atoms per unit charge, they are likely to contain multiple hydrogen bonding systems [see e.g. Adams & Small (1974). Acta Cryst. B30, 2191–2193], which are of interest in themselves and are also likely to cause stabilization of the structure. The crystal data of a range of salts were collected and are given. Space group and approximate cell dimensions were obtained from oscillation and Weissenberg photographs. Powder diffraction data [0° to 60° (2&thgr; using Cu Kα)] were indexed and the cell parameters refined using the programs PIRUM of Werner [Program No. 1, World List of Crystallographic Computer Programs (3rd. ed.): J. Appl. Cryst. (1973). 6, 309–346] and CELFIT of Bracher [UKAEA Research Report, AERE-R5412 (1967)].
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 397-397 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Unlike the position with negatively charged substituents, little has been done on benzaldehydes ortho-substituted with positively charged groups. This is more especially true in the field of crystallography where only the X-ray and neutron diffraction study of o-nitrobenzaldehyde has been reported [Coppens & Schmidt, Acta Cryst. (1964). 17, 222–228; Coppens, Acta Cryst. (1964). 17, 573–578]. Preliminary results of a structural investigation on Se- and Te-containing benzaldehydes are presented. The main purpose is to corroborate and to complete the conclusion of recent n.m.r. work on the conformation of these molecules [Baiwir, Llabres, Denoel & Piette, Mol. Phys. (1973). 25, 1–7]. The following compounds have been studied: C6H4.COH.TeCl, C6H4.COH.TeBr, C6H4.COH.TeI, C6H4 COH.SeCl, C6H4.COH.SeBr. The crystal structure of the second (TeBr) has been recently reported [Baiwir Llabres, Dideberg, Dupont & Piette, Acta Cryst. (1974). B30, 139–143] and the structure of the last (SeBr) is presently in the final stage of refinement.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 402-402 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 403-403 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 405-414 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Quantitative liquid-structure analysis using energy-scanning diffraction rather than the traditional angle-scanning diffraction is introduced. In the experimental method, white radiation and a solid-state detector are employed. This new method is inherently faster and less beset with problems of experimental instability than are angular-scanning methods. However, many differences in analysis are introduced. In particular, measurement of the primary beam spectrum, the nature of the absorption and dispersion corrections, details of the polarization correction, the ranges of the atomic scattering factor and of the incoherent scattering term, and the mating of different scattering regimes all require special consideration. Application of the new instrumental method and the reconstructed analytical procedure to liquid mercury at room temperature has produced a result in agreement with other recent studies.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 421-429 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A new small-angle X-ray scattering facility which utilizes a 6 kW rotating anode, pin-hole collimation, and a position-sensitive proportional counter has been developed. As presently constructed, the minimum scattering vector κ (= 4π sin &thgr;/2) which can be reached with Cu Kα radiation is 5 × 10−3 Å−1. Under these conditions the flux incident on the specimen has been found to be 6 × 105 photons s−1. The system has several advantages compared with traditional long-slit geometries; namely, (i) it can quantitatively measure anisotropic scattering distributions, (ii) it avoids large mathematical corrections of the data for slit-smearing effects, and (iii) it minimizes double Bragg scattering in crystalline materials and multiple diffuse scattering in amorphous or liquid materials. To illustrate the performance of this instrument, the scattering curves obtained from four widely different samples are shown. These are: polyethylene, a neutron-irradiated aluminium single-crystal containing voids, a dilute suspension of Ludox spheres, and duck tendon collagen. Quantitative comparisons of the performance with a Kratky camera and with the neutron small-angle scattering facility in Jülich are given.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 457-458 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The lattice constants of a diamond platelet and of large single, undoped, crystals of silicon and germanium have been determined from measurements of multiple diffraction patterns by the method described in Part I [Post (1975). J. Appl. Cryst. 8, 452–456]. The mean values, based on measurements of eight to twelve reflections, and their standard deviations are: diamond a = 3.566986 Å, Aa/a = 2.6 × 10−6; silicon a = 5.430941 Å, Aa/a = 2 × 10−6; germanium a = 5.657820 Å, Δa/a = 1.6 × 10−6.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 469-472 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The Mn3+ site distribution in a manganese-containing tsilaisite tourmaline sample has been determined as 46±3 wt. % in the larger Y octahedral sites and 54± 3 wt. % in the smaller Z octahedral sites. For this, a novel application of anomalous X-ray scattering techniques, in conjunction with the energy dispersive X-ray diffraction procedure, has been used. This method appears to be versatile and applicable to many different elements.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 491-492 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: An inexpensive calculation is outlined for determining those reflexions suffering large absorption errors, and for correcting those with smaller errors.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 496-496 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 496-497 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 375-379 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The lattice parameters and the linear coefficient of the lattice thermal expansion of f.c.c. β-Cu2−xSe (1.86 ≥ 2−x ≥ 1.72) were determined by means of the Debye–Scherrer X-ray diffraction technique in the temperature range 25–336°C. The concentration and temperature dependence of the coefficient of thermal expansion are discussed. In addition the equilibrium phase diagram of the Cu–Se system in the region of a non-stoichiometric Cu2−xSe compound (2.00 ≥2−x ≥1.72) was redetermined, with special consideration of the homogeneity range of the f.c.c. β-Cu2−xSe, and compared with previously published results.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 391-391 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Crystals of Tl2GeS3 were grown by solidification from melts. The compound is triclinic with lattice parameters a = 8.06, b = 12.70, c = 6.76 Å, α = 96°39′, β = 93°10′, γ = 99°31′. Powder data are given.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 589-597 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A computer program has been written in Fortran for the numerical calculation, using generalized spherical harmonics, of the texture of a sample, even when it has no symmetry. Automatically plotted pole figures, corrected and normalized, make it possible to begin to control the results. Reconstituted pole figures are plotted as a function of Cmνl. The calculations, based on the theoretical developments of Bunge [Mathematische Methoden der Texturanalyse. (1969). Berlin: Akademie Verlag] were carried out with different numerical analyses so as to reduce the size of the calculation and the time taken.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 578-581 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The white X-ray diffraction method with the use of a powder sample [Laine, Läihteenmäki & Kantola (1972). X-ray Spectrosc. 1, 93–98] was improved by paying special attention to the following four points: (i) the determination of the energy spectrum of incident white X-rays, (ii) the measurement of the energy dependence of the relative absorption coefficient, (iii) the correction for the contribution from thermal diffuse scattering, and (iv) the correction for the anomalous dispersion. The determination of the structure factors of GaP is shown as an example of its applications. The structure factors determined were compared with those obtained by the usual angle dispersive method with monochromated X-rays on the same sample. It is shown that these two sets of structure factors mostly agree within the limit of reproducibility.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 612-614 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The errors in the Fourier coefficients of the α1 component obtained by α2 elimination are investigated analytically. The effects of counting statistics, of an incorrect intensity ratio of the α1 and α2 components and of an incorrect doublet separation are calculated. The mean-square error in the Fourier coefficient caused by counting statistics is a periodic function of the harmonic number, while errors in the intensity ratio and in the doublet separation primarily affect the first Fourier coefficients. The results are confirmed by computer simulations and by computations with experimental line profiles. The α2 elimination methods assume a perfect shape identity of the α1 and α2 components, but this assumption is not completely justified. Deviations might be interpreted as local errors in the doublet separation and the intensity ratio.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 628-635 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The textures of undirectionally and reversed rolled aluminium sheets were measured using thermal neutrons and Cu and Mo Kα radiation. The samples for the X-ray measurements were prepared in three different ways so that the degree of correspondence between textures as measured with neutrons and X-rays could be investigated. It is shown that agreement can be achieved if the X-rays used penetrate sufficiently into the sample and if a composite type sample is used.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 329-332 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Kyanite phases Al2SiO5 (I), Al2GeO5 (II) and Cr2GeO5 (III) were synthesized at 20 kb/1000°C (I, II) and at 1 atm/1150°C (III). Powder X-ray patterns for II and III are presented in comparison with that of I. Triclinic lattice constants are a0 = 7.127 (7.253, 7.422), b0 = 7.858 (8.011, 8.244), c0 = 5.570 (5.649, 5.815) Å, α = 89.99 (89.97, 90.58), β = 101.22 (101.23, 101.10), γ = 106.04 (106.05, 106.01)°, and V0 = 293.6 (308.9, 339.9) Å3 for the kyanite phases I (II, III, respectively). Infrared absorption spectra of I (II, III) were measured between 1400 and 200 cm−1. Band shifts produced by the isomorphous substitutions allow tentative band assignments of the Al2SiO5-kyanite spectrum: 1032, 1009, 940 cm−1 ν3 (SiO4); 898 cm−1 ν1 (SiO4); 720, 438 cm−1 ν4, ν2 (SiO4) ?; banes between 674 and 505 cm−1 and at 467 cm−1 are mainly due to octahedral Al–O vibrations.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 343-344 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 343-343 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 352-355 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: An attractive use of a convergent-beam camera is described. Its advantages, with respect to classical methods, are pointed out. The short exposure time provided by this device is very useful in the selection and detailed study of polytypic crystals. Some X-ray photographs obtained from a titanium sulphide polytypic crystal are displayed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 365-371 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Solids characterized by lamellar structure are often made from ribbon or lath-shaped sheets. Such a morphology has been observed in phyllosilicates (hectorite or nontronite, for example) and in carbon fibres. This contribution aims to show that elongated planar sheets can be detected from the profile of the X-ray diffraction bands yielded by the powdered solid. The numerical technique originally developed by Brindley & Méring [Acta Cryst. (1951). 4, 441–447] for isometric layers, has been extended to ribbon or lath-shaped elementary layers. An example of application is given when the sheet is a carbon layer.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 380-385 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: About fifty X-ray powder diagrams were recorded in the range 15 to 295 K, by means of a prototype diffractometer and a high-efficiency cryostat, so that a very precise study of the anisotropic structural evolution of ferrocene could be made. The cell parameters and volume have been computed. These parameters present a discontinuity at 164 K; the cell is triclinic below and monoclinic above this temperature. The transition is first order. The principal thermal expansion coefficients have been computed and their evolution, in terms of temperature, has been related to the anisotropic change of the intermolecular contacts in the crystal. Assumptions about the mechanism of transition and about the ferrocene configuration in the ordered phase are expressed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 388-389 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A graphical construction on the Wulff net permits corrections on both arcs and the dial to be determined even if neither of the arcs is parallel to the film and/or the outer arc reading is large. The procedure requires that the orientation errors be multiplied by an arbitrary common factor smaller than ten, while the biggest multiplied error should be less than ten degrees: the corrections are obtained graphically and divided by the factor. Corrections thus obtained are within 10% of their true values.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 398-400 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Tl2Mo7O22 is monoclinic with space groupe C2/c or Cc and with a = 20,512 (6); b = 5,526 (2); c = 19,460 (6) Å; β = 125,20 (3)°: Z = 4. Tl2Mo4O13 is orthorhombic with space group Pbca and with a = 7,583 (3); b = 15,409 (3); c = 18,798 (3) Å; Z = 8. Tl7Mo2O7 is monoclinic with a = 8,427 (2); b = 5,690 (2); c = 7,935 (2) Å; β = 108,90 (2)°; Z = 2. The indexed powder diagrams are given.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 402-402 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 8 (1975), S. 403-403 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 307-310 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Transparent yellow-greenish single crystals of Pb6GeO8 were obtained by spontaneous crystallization from a melt with a molar ratio of PbO:GeO2 = 4.7:1. The compound is monoclinic, probable space group P21/a, a = 52.665 (12), b = 15.063 (4), c = 23.949 (6) Å and β = 111.03 (5)°; Dm(293 K) = 8.65 (3), Dx = 8.653 Mg m−3 for Z = 64 formula units. Pb11Ge3O17 was synthesized by sintering high-purity oxides PbO and GeO2 of molar ratio 3.69:1 at 990 K. The compound is also monoclinic, probable space groups C2/c or Cc, a = 25.117 (5), b = 15.440 (2), c = 45.529 (13) Å and β = 103.20 (4)°; Dm(293 K) = 8.55 (2), Dx = 8.560 Mg m−3 for Z = 32.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 311-315 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Series of chalcopyrite-type solid solutions AgGaxIn1−xSe2 and CuGaxIn1−xSe2, 0≤x≤1, have been prepared by direct synthesis from the melt. The space group is I\bar 42d (No. 122), Z = 4. The unit-cell parameters a and c and the ratio c/a change linearly with x. Powder data at 298 K are given for AgGaSe2, AgGa0.80In0.20Se2, AgGa0.70In0.30Se2, AgGa0.40In0.60Se2, AgGa0.20In0.80Se2 and AgInSe2, and for CuGaSe2, CuGa0.60In0.40Se2, CuGa0.30In0.70Se2 and CuInSe2.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 318-337 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 338-339 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: If the length of the focal spot is increased while the width remains constant, X-ray output can be increased without changing the specific loading on the anode.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 391-394 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: To increase the integrated reflexion intensity of a monochromating crystal, the strain distributed due to impurity introduction can be utilized and, compared with conventional mechanical processing, can be a more controllable method. From this viewpoint, numerical computations on the dynamical diffraction theory for distorted crystals have been performed for the 220 reflexion of Cu Kα X-rays by Si crystals with several different strain distributions; the one changing linearly with depth from −10−3 at the surface to zero at 28 μm depth gives the maximum integrated intensity within the restriction that the full width of the intensity profile is 100′′. The integrated intensity in this case is 5.3 and 4.5 times as strong as that of a perfect crystal plate for σ and π polarizations respectively. It is more enhanced for shorter wavelengths, e.g. nine times for Mo Kα. In addition, that intensity profiles for distributed strains are cut sharply at both ends is certainly favourable for the purpose of monochromating white X-rays. A preliminary experiment with an intentionally processed sample showed a fourfold intensity increase for a σ-polarized Cu Kα line with a full width of 80′′.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 401-401 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 88-92 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The device described here has been designed to perform microcreep experiments and, simultaneously, to get X-ray topographic images of the sample. Such dynamic experiments are now possible with white synchrotron radiation (LURE-DCI Orsay). The sample material, germanium, is hard to machine; so a simple shape was chosen (rectangular platelet 20 × 5 × 0–2 mm). The grip system is quite simple and the whole assembly is compact enough to be adapted to fit a standard goniometer head. Temperatures as high as 923 K in air and forces up to few tens of Newtons can be reached. The first experiments on Ge bicrystals have shown the device to perform as expected.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 78-87 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A polished plate of type Ia natural diamond, containing regions which had been bombarded by electrons of energy between 2.0 and 4.5 GeV to total doses of 1̃024 electrons m−2 in polarized-photon production experiments, was examined, both before and after annealing at 1133 K for 8 h, using birefringence, cathodoluminescence photography and spectroscopy, X-ray topography and a novel method for mapping differences of interplanar spacing; `dilatation topography'. The annealing effected some reduction of overall strain, but it also generated an enhancement of diffraction contrast and cathodoluminescence at certain grown-in defects that the specimen contained. By means of dilatation topographs, interplanar spacings in a region of maximum electron-beam damage were compared with those in least-damaged regions some millimetres away. In the case of (110) planes that had been grazed by the electron beam, the maximum relative expansion, Δd/d, in damaged regions so found was reduced from 1.2 × 10−3 to 0.9 × 10−3 by the annealing. Evidence was obtained that the magnitude of expansion in the region of maximum damage was dependent upon crystallographic direction. Criteria are suggested for selection of diamonds to be used in polarized-photon production experiments.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 93-95 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Cell data for monoclinic sebacic acid COOH(CH2)8COOH, C10H18O4, and dodecanedioic acid COOH(CH2)10COOH, C12 H22O4, are accurately given: (C10) a = 15.064 (6), b = 4.987 (4), c = 10.142 (6) Å, β = 133.14 (5)°; (C12) a = 17.594 (8), b = 4.933 (3), c = 10.174 (5) Å, β = 132.35 (3)°. It is shown that crystallographic data for molecular alloys [C10]x[C12]1 −x are significantly different for those prepared by fusion (m.a.f.) and those by sublimation (m.a.s.). X-ray powder data are given for the two series of solid solutions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 95-96 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The cell constants for the title compound, HMTSFT–CNQ4, (C12F4N4).(C12H12Se4), M.W. 748.21, were determined from a single crystal exposed on a Syntex P{\bar 1} automated diffractometer and then refined from precision powder data with Cr Kα1 (2.28962 Å): a = 21.906 (5), b = 12.918 (3), c = 4.0184 (10) Å and β = 91.658 (10)°; U = 1136.7 Å3, Z = 2, space group C2/m; Dc = 2.186 Mg m−3.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 128-131 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A &psgr;-φ goniometer with two axes of rotation, driven by stepping motors, was designed as an attachment for a horizontal &thgr;/2&thgr; goniometer. By means of this arrangement it is possible to measure strains and compute stresses in single crystals and in separate crystals of a bicrystal or a coarse-grained polycrystalline specimen. The available rotations also make it possible to investigate residual macrostresses and textures in polycrystalline specimens. Results of the test measurements on a tensile specimen of a molybdenum single-crystal are given.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 132-134 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A calculation of γ(r), the correlation function which gives the X-ray scattering of a cubic object of uniform density, is given for the full range of r. A new method, which can be applied to other systems, is used. The function γ(r) and its first derivative are everywhere continuous, but γ′′(r) is discontinuous at r = L and r = L□2 (L = cube edge length). This leads to an intersect distribution of unexpected shape. The scattering intensity as a function of angle is calculated by Fourier inversion of γ(r).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 135-140 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: An experimental method is described which enables the inelastically scattered X-ray component to be removed from diffractometer data prior to radial density function analysis. At each scattering angle an energy spectrum is generated from a Si(Li) detector combined with a multi-channel analyser from which the coherently scattered component is separated. The data obtained from organic polymers has an improved signal/noise ratio at high values of scattering angle, and a commensurate enhancement of resolution of the RDF at low r is demonstrated for the case of PMMA (ICI `Perspex'). The method obviates the need for the complicated correction for multiple scattering.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 148-153 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Until now, the calculation of intensities diffracted by layer structures has only been treated in the two extreme cases, namely (i) the layers interfere completely and (ii) the layers do not interfere (turbostratic structures). The present paper develops the mathematical treatment which allows the calculation in the intermediate case, namely when layers are only partially interfering.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 141-147 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A niobium tungsten bronze crystal with a nominal composition 3 Nb2O5.8WO3 gives circular diffuse scattering in the electron diffraction pattern. The diffuse rings change shape and size when the crystal is reduced at high temperature. The observations are explained by improving the cluster model proposed by De Ridder, Van Tendeloo, Van Dyck & Amelinckx [Phys. Status Solidi A (1977), 41, 555–560]; the present clusters are composed of nine pentagonal-tunnel sites. The 1 MV high-resolution electron microscope images reveal that the clusters have several different atomic arrangements and compositions. The relation between the clusters and the micro-domains, formed in the initial stage of long-range ordering, is clarified.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 163-167 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Analysis of Bragg X-ray intensities collected on a single-crystal diffractometer with a pyrolitic graphite monochromator in the diffracted beam has revealed small systematic errors which are a consequence of the necessarily large illuminated area of monochromator crystal.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 154-162 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The amount of information which can be obtained from a small-angle X-ray experiment can be considerably increased by orienting the solute particles with external forces during the scattering experiment. In this paper it is shown that orientation by flow, for instance through a capillary tube, gives additional information about size, shape, flexibility and rotational diffusion of the particles. The only requirement, in order to obtain flow-oriented samples, is that the solute particles must be relatively large and asymmetric. On the other hand, if the scattering curve is dependent on the flow rate through the capillary, it can immediately be concluded that the solute particles are asymmetric (or they are deformed in the hydrodynamic field). Equations describing the relationship between flow rate, molecular shape and scattered intensity are given, and theoretical intensity patterns for some representative cases are presented. It follows that there is a fundamental difference in scattering patterns for oblate and prolate ellipsoids of revolution. This difference can be used to differentiate between these two cases. Some experimental results obtained using inorganic model colloids are presented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 168-175 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: An analysis of the small-angle scattering problem based on Shannon sampling is presented. It is shown that this approach leads to an accurate assessment of the information contained in a given data set and rigorous estimates of the errors inherent in the parameters derived therefrom.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 401-402 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 605-607 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The crystal structure of Ta5P3 has been refined from Guinier–Hägg X-ray powder film data [Malmros & Thomas (1977). J. Appl. Cryst. 10, 7–11] using positional parameters from its structural isomorph Nb5P3 as starting values. The space group is orthorhombic Pnma (No. 62), with refined cell parameters a = 25.3210 (4), b = 3.4013 (1), c = 11.4614 (2) Å, V = 987.12 (5) Å3 and Z = 4. Final R = 4.9% [comparable with the R(F) of single-crystal work]. The structure exhibits the triangular prismatic Ta coordination about the P atoms and the dense packing of the Ta atoms, both familiar in many metal-rich phases formed between transition metals and non-metals of type P, As, S and Se.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 611-611 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: In the paper Revised and new crystal data for indium selenides by Popovic, Tonejc, Grzeta-Plenkovic, Celustka & Trojko [J. Appl. Cryst. (1979), 12, 416–420] it was concluded that P6122 or P6522 was the probable space group of the second high-temperature, γ, phase of In2Se3. Also, in the paper Phases, lattice parameters and thermal expansion of (GaxIn1−x)2Se3, 1 ≥ x ≥ 0, between room temperature and melting point by Tonejc, Popovic & Grzeta-Plenkovic [J. Appl. Cryst. (1980), 13, 24– 30] the same space groups were suggested for the phase γ1, existing in the In-rich region. However, the space group in both cases should be P61 or P65. This is in agreement with the work of Likforman, Carré & Hillel [Acta Cryst. (1978), B34, 1 5] who solved the crystal structure of one of the forms of In2Se3, and with the work of Schulte-Kellinghaus & Krämer [Acta Cryst. (1979), B35, 3016 3017] who solved the crystal structure of AlInS3. Likforman, Carré & Hillel [Acta Cryst. (1978), B34, 1 5] call their phase the low-temperature form of In2Se3.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 340-341 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 342-342 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 354-358 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Image formation in a dispersive system, consisting essentially of a perfect cylindrically bent crystal in association with a point source, has been studied both for transmission and reflection. The Laue and Bragg conditions have been calculated together with the dispersive power. The treatment has been extended to include two crystals. In the single-crystal case and also for most versions of two-crystal combinations a point or line focus is required to obtain highly resolved spectra. A few versions of the two-crystal arrangement can be made to be focusing, thereby enabling the use of an extended radiation source.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 364-367 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Zone-axis pattern maps for graphite have been obtained using multiple-micrograph montages. Maps have been constructed with bend-contour micrographs and with Kossel–Möllenstedt patterns, both obtained at 100 kV. The two kinds of map are compared.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 385-390 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Analytical explicit expressions have been derived for multiple-scattering effects under assumptions which are usually fulfilled in small-angle scattering. The expressions are used to evaluate quantitatively distortions of scattering patterns caused by multiple scattering. The distortions are discussed in terms of changes of the forward-scattering cross section, the radius of the gyration, the integrated intensity, the Porod region and Porod constant. In addition, the analytical expressions have been used to calculate the scattering cross section of the sample from scattering patterns which are strongly affected by multiple scattering.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 401-401 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 403-409 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The phases of ammonium nitrate, NH4NO3, doped with small amounts of NiO or CuO have been studied by X-ray and neutron diffraction at various temperatures from 80 to 423 K. NH4NO3 with metal-oxide additives, which are believed to form complexes, exists as a solid solution. Phase IV is stable down to 140 K in the NiO-doped samples and 210 K in the CuO-doped sample. The thermal expansion of this phase is extremely anisotropic, with the b axis expanding rapidly with increasing temperature while the a axis contracts slightly. At higher temperatures the doped samples transform directly from phase IV to phase II, bypassing phase III, starting at about 328 K. The structure of phase II, which is disordered, was refined in the space group P4/mbm. The structure of phase III contains hydrogen-bonded chains parallel to the b axis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 433-437 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A white-X-ray (Bremsstrahlung) four-circle diffractometer with a solid-state detector [Si(Li)] has been constructed. The system is operated by a small computer with magnetic disk memories, and enables energy-dispersive intensity measurements to be carried out with the X-rays selected from white X-rays. The present paper describes (1) how the present system can be used for energy-dispersive diffractometry even with the white radiation from a standard X-ray tube, and (2) how this system allows the measurement of the integrated intensities with almost the same accuracy as in angle-dispersive diffractometry with characteristic X-rays.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 425-432 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A unique low-temperature, full-circle goniometer for single-crystal X-ray diffraction has been constructed with the novel adaptation of a closed-cycle refrigerator in such a manner that the cold finger remains stationary during the φ and χ rotations. This has been made possible through the development of a flexible heat-transfer link between the top of the φ shaft and the cold station. The new design concept incorporates several important features: (1) the vacuum shroud and radiation shields also remain stationary so as to reduce the X-ray windows to narrow slots; (2) the sample crystal is enclosed in a black, nearly isothermal cavity (Hohlraum); and (3) the φ shaft is mechanically decoupled from the thermal contraction of the cold finger and other parts. The new system has considerable advantages over presently existing low-temperature adaptations for X-ray diffraction: (1) the goniometer operates between 300 and 18 K without expenditure of liquid cryogen and with minimal attendance; (2) the system is capable of operating for long periods of time with minimal risk of interruption of the cooling cycle; (3) absorption of X-rays by the windows is minimal and independent of the Bragg angle; and (4) data collection at any temperature down to its present lowest limit of 18 K is virtually as easy as with any conventional room-temperature diffractometer. At the time of writing the instrument has been in use for over 10000 h and has measured over 100000 X-ray reflections from single crystals.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 459-461 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A RAdial Distribution MOdeling Routine (RADMOR) is available which calculates directly the radial distribution function that would be obtained from electron, X-ray and neutron diffraction for spherical regions of known bonding topology. Crystalline as well as model fragment topologies can be evaluated in modeling the atomic arrangement in amorphous materials.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 462-462 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 465-471 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: The performances of various optical elements are presented for ideally monochromatic X-rays in terms of position–angle space, which is used in the phase-space method. The optical elements discussed are a synchrotron radiation source, flat perfect crystals (reflection and transmission geometries), mosaic crystals, curved crystals of reflection (Johansson, Johann and logarithmic spiral types) and transmission geometries, and an elliptic total reflection mirror. The angular widths of acceptance and emergence for diffraction are properly taken into account in both the flat and curved crystals. It is shown that focusing optical elements such as a curved crystal and an elliptical mirror should not be treated simply as lenses.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 486-493 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Both superlattice and fundamental reflections have been used in an X-ray determination of the vanadium-atom displacements induced by selected ordering of interstitial deuterium in a multi-domain crystal of V2D. The magnitudes of these displacements along X and Z directions of the pseudo-tetragonal (b.c.t.) unit cell are designated DAX and DAZ respectively, where Z is along the tetragonal c axis. Measurements of the lattice parameters yield DAX ∼0.03 and DAZ ∼0.17 Å. From intensity measurements, the best values for the displacements are DAX = 0.03±0.01 and DAZ = 0.15±0.02 Å, and the purely thermal Debye–Waller factor was found to be 2B = 0.025 Å2. The temperature dependences of both the long-range-order parameter, S, and the lattice parameters of the b.c.t. unit cell were also investigated. Both verify that the phase transition from β (monoclinic) to α (b.c.c.) is first order in character with no intervening ε (tetragonal) phase as in V2H. There is additional evidence that the disordering process includes random occupancy of both Z octahedral and random tetrahedral sites.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 505-512 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: One lamellar phase, observed in the mitochondrial lipids–water system at low temperature (ca 253 K) and at low water content (ca 15%), contains four lipid monolayers in its unit cell, two of type α and two of type β. Previous X-ray scattering studies of this phase led to an ambiguity: the phase could contain either two homogeneous bilayers, one α and one β, or two mixed bilayers, each formed by an α and a β monolayer. A solution to this problem was sought in a neutron scattering study as a function of the D2O/H2O ratio. Because of limited resolution, straightforward analysis of the neutron scattering data leads also to ambiguous results. Using a more sophisticated analysis based upon the zeroth- and second-order moments of the Patterson peaks relevant to the exchangeable components, it is shown that the weight of the evidence is in favour of a structure containing mixed bilayers.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 13 (1980), S. 529-532 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: At the IA magnetic transition (12.5 K) in CeBi a theoretical study has suggested that either the Ce or Bi sublattices should move with respect to the other. Such a distortion would give rise to extra reflections of the form 0′0′l+½. A search for such a reflection using a Bond X-ray diffraction technique was conducted. The 007½ line was not found and an upper limit of 2̃ × 10−4 was set for the magnitude of the expected internal distortion. This limit is valid for a surface layer whose thickness equals the penetration depth of the X-radiation which is about 0.4 × 10−2 mm.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    Electronic Resource
    Electronic Resource
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 31 (1975), S. 1-7 
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: The resolution function is derived for a three-axis neutron spectrometer in which the monochromator scattering plane is at an angle to the specimen and analyser scattering planes. The analysis shows that the width of measured peaks is much more affected by the slope of the dispersion surface under investigation than by the angle between the planes. It is concluded that a spectrometer which is used on a hole inclined at 35° would have satisfactory resolution and intensity for most purposes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Electronic Resource
    Electronic Resource
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 31 (1975), S. 80-83 
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: In anthrone (10H-anthracen-9-one) crystals there may be two distinct types of molecular orientational disorder. Firstly, whole stacks of molecules along [010] may, by association with vacancies, become orientationally disordered between positions related by a twofold screw axis in the crystal. Secondly, individual molecules may become disordered between orientations related by inversion through the molecular centre of mass. Calculations with previously developed Ising-like models (with an atom-atom intermolecular potential, the data for the low-temperature unit cell and the observation of a transition temperature at 357K) reveal that at 295K both types of disorder are present. This explains previous detailed X-ray diffuse-scattering data. Parts of these data give 16 ± 1, 36 ± 9 and 25 ± 2 Å for the observed range of the order in the a, b and c directions. The calculations predict 16 ± 0, 37 ± 12 and 24 ± 6 Å.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    Electronic Resource
    Electronic Resource
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 31 (1975), S. 130-135 
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: A theoretical analysis of X-ray diffraction from asymmetric planar systems is given. Phase information is obtained from the continuous intensity function from such a system. Although a unique phase function cannot be determined, it is possible to derive the relatively small number of phase solutions which are consistent with the observed diffraction.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    Electronic Resource
    Electronic Resource
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 31 (1975), S. 116-125 
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: A theory for the contrast from phonon-scattered electrons is presented. In this theory single-phonon scattering is taken into account. The influence of the strain field of the crystal defect on the electrons which have been scattered by phonons is considered dynamically. The dislocation contrast in the thermal diffuse intensity is calculated under weak-beam conditions at 100 kV and 1MV. It is shown that the thermal diffuse and elastic intensities are comparable in magnitude for foil thicknesses of the order of the mean free path for electron-phonon scattering. The thermal diffuse intensity has a minimum close to the position of the dislocation. The dependence of the visibility in weak-beam images on the foil thickness, the accelerating voltage, the aperture radius and the temperature is discussed. The diffuse intensity from contaminating carbon layers has been estimated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Three-dimensional intensity profiles of selected diffuse b-type (h + k = odd) reflections in a core pigeonite from lunar rock 12053 have been measured by a point-count method using a single-crystal automatic diffractometer. Sampling reciprocal space about a Bragg reflection yields a 5 × 5 × 5 array of intensity data; contouring shows the shape, size and orientation of the diffuse reflection. It is assumed that the intensity distribution is Gaussian in reciprocal space and the diffuseness of the b-type reflections is primarily due to small antiphase domains. From the intensity data, the average shape, size and orientation of the antiphase domains have been determined by applying Fourier transform theory. The average shape of the antiphase domains can be approximated by an ellipsoid with axial lengths; {\bar z} = 171, ÿ = 141, and {\bar x} = 122 Å. Lengths of these axes have been adjusted by a correction factor which makes the adjacent a-type (h + k = even) reflection conform to its ideal spherical form. The long (z) axis deviates from the crystallographic axis and forms a 44° circle about {\bar 2}11. The average size and shape of the domains agree well with those determined through electron microscopy.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Electronic Resource
    Electronic Resource
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 31 (1975), S. 136-141 
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: A quantitative knowledge of the refractivities and anisotropies of some organic molecules, aromatic and aliphatic, of different shapes and containing various electronic groupings was obtained. The studied aromatic compounds include three rings and one ring with different substituents while the aliphatic compounds contain six-membered rings, five-membered rings and open chains. The results show that strong magnetic anisotropy is always associated with strong optical anisotropy, and the optical anisotropy of the molecules divided by that of the benzene molecule is smaller than the corresponding value for magnetic anisotropy. Also the optical anisotropy in the case of aromatic compounds is markedly decreased by substitution.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Electronic Resource
    Electronic Resource
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 31 (1975), S. 146-148 
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Accurate X-ray absorption correction factors A* for cylindrical samples were calculated in the range of the product of linear absorption coefficient μand cylinder radius R of 0 ≤ μR ≤ 2.5 and in the range of Bragg angle θ of 0° ≤ 0 ≤ 90°. A method of double numerical integration that is different from the method usually used resulted in a maximum error of 0.1% with the typical error being much less. A table of values of A* was prepared, and simple equations were obtained for interpolation between values in the table to an accuracy of 0.1% or better. A full-range curve-fitting procedure that is accurate to 0.1% also was developed for routine use when many values of A* must be calculated for a single sample.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    Electronic Resource
    Electronic Resource
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 31 (1975), S. 142-145 
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: A method previously developed for high-precision orientation of low-index planes of perfect or nearly perfect crystals has been extended to planes with arbitrary indices. The extension has been accomplished by predicting the back-reflexion patterns of Laue spots due to characteristic X-rays and by identifying spots which should have equal intensity when the correct orientation is obtained. It is possible to orient the specimen crystal within 0.01° of the desired orientation in favourable cases. In cases where the equal-intensity criterion cannot be used the accuracy of the orientation using the predicted pattern is at least as good as that using the conventional Laue method. Furthermore there is no need to measure angular distances between the spots or the distance between the crystal and the film.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 31 (1975), S. 149-152 
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: The values of the second, third and fourth-order moments of the normalized intensity z and the maximum probable values of two types of discrepancy index, namely RB and R2, are worked out for various types of pseudosymmetric structures considered by Rogers & Wilson [ Acta Cryst. (1953). 6, 439-449].
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    Electronic Resource
    Electronic Resource
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 31 (1975), S. 153-155 
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Several serious errors which were included in a paper entitled Multiple diffraction of X-rays and the phase problem by R. Colella [Acta Cryst. (1974). A30, 413-423] are noted and discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    Electronic Resource
    Electronic Resource
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 31 (1975), S. 155-155 
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: It is shown that the errors in the paper by R. Colella [Acta Cryst. (1974). A30, 413-423] pointed out by B. Post [Acta Cryst. (1975). A31, 153-155] do not in fact exist.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...