ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Third-order nonlinear optical properties of sol–gel derived α-Fe2O3, γ-Fe2O3, and Fe3O4 thin films (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 3184-3190 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The third-order nonlinear optical properties of sol–gel derived α-Fe2O3, γ-Fe2O3, and Fe3O4 thin films have been investigated by the third-harmonic generation method. Especially, the effects of the valence and coordination number of Fe ions on the third-order nonlinear optical susceptibility, χ(3), have been examined. The χ(3) values of α-Fe2O3, γ-Fe2O3, and Fe3O4 thin films were 5.8×10−11, 2.1×10−11, and 4.0×10−10 esu, respectively, which are the highest values among inorganic oxides reported so far. It was considered that χ(3) of α-Fe2O3 and γ-Fe2O3 was enhanced by the pair excitation process involving the simultaneous excitation of magnetically coupled two neighboring Fe3+ ions as well as by virtual transition from O 2p orbitals to Fe 3d orbitals while χ(3) of Fe3O4 was enhanced by both one- and three-photon resonances. The higher second hyperpolarizability, γ(Fex/yO), was obtained when Fe ions are 3+ rather than 2+ and octahedrally rather than tetrahedrally coordinated by oxygens. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.363258
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Phase matching of rutile single crystal (1996)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 68 (1996), S. 2478-2479 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Phase matching for the third-harmonic generation (THG) of rutile single crystal (110) at 1.9 μm has been investigated. THG with a visible red light (633 nm) was clearly observed, indicating that TiO2 (rutile) is one of the most promising third-order nonlinear optical materials. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.115826
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Fusion properties and heat capacities of the eutectic lithium fluoride-sodium fluoride-potassium fluoride melt (1982)
    s.l. : American Chemical Society
    Journal of chemical & engineering data 27 (1982), S. 366-367 
    Details
    ISSN: 1520-5134
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/je00029a041
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Ab initio cluster model calculations on the boson peak frequencies of B2O3 glass (1996)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 105 (1996), S. 4140-4150 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We have performed ab initio molecular orbital calculations on the clusters modeling the medium-range ordering (MRO) region of B2O3 glass at the Hartree–Fock (HF)/3-21G and HF/6-31G* levels. Their equilibrium geometries, harmonic vibrational frequencies, and Raman scattering intensities have been calculated. The calculations have reproduced the boson peak frequencies of vitreous B2O3 observed at ≈24 cm−1 and ≈137 cm−1. The normal coordinates have demonstrated that these low-frequency vibrational modes are due to the wavelike motions of atoms within the region composed of one (for the mode at ≈137 cm−1) or two (for the mode at ≈24 cm−1) boroxol ring(s). The results suggest that the boson peak originates from the collective vibrations localized in the MRO region of glasses. We also propose that in glasses there are localized potential surfaces that are defined by the atoms in the medium-range scale. The driving force of the fast β relaxation will be the cooperative motions of atoms at the unstable sites toward the stationary point on the localized potential surface, which occasionally leads to the formation of the MRO region. We then interpret the glass transition phenomena and the strong/fragile differentiation of glasses in terms of the restoring force on the localized potential surface. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.472284
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Localized low-frequency dynamics in SiO2 glass (1998)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 108 (1998), S. 8130-8138 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We have carried out ab initio molecular orbital calculations on a cluster of atoms modeling the medium-range structure in SiO2 glass to investigate its low-frequency vibrational properties. The model cluster is composed of several types of n-membered silica rings (n=3, 4, 5, and 6), and its geometry was completely optimized at the Hartree–Fock/3-21G(*) level. We have shown that the optimized structural parameters (the average Si–O, O–O, and Si–Si bond distances Si–O–Si and O–Si–O bond angles) are in good agreement with the observed ones. The three- and four-membered rings resulted in regular geometries, namely, a nearly planar and a puckered configuration, respectively, whereas the optimized geometries of the five- and six-membered rings were rather distorted. The frequency calculations on the cluster have demonstrated that relative rotations of the SiO4 tetrahedra occur in the low-frequency (≤150 cm−1) vibrational region. The calculated vibrational density of states exhibits a maximum at ∼45 cm−1 that matches the observed "boson peak" of SiO2 glass. These rotational motions of the SiO4 tetrahedra have shown to be localized in the four-, five-, and six-membered rings, and the resonant frequencies increase with decreasing ring size. We have also found that collective rotations of the SiO4 tetrahedra exhibit transverse-type acoustic modes. These localized dynamics on the medium-range length scale is a possible mechanism for the anomalous low-frequency harmonic excitations in SiO2 glass called the boson peak. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.476253
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Structural Study on PbO–SiO2 Glasses by X-Ray and Neutron Diffraction and 29Si MAS NMR Measurements (2005)
    Oxford, UK : Blackwell Science Inc
    Journal of the American Ceramic Society 88 (2005), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Structure of xPbO–(100−x)SiO2 (x=25–89) glasses has been investigated by means of the X-ray and neutron diffraction and 29Si MAS NMR measurements. In the radial distribution functions of all the glasses, the Pb–O correlation was observed at 0.23 nm, indicating that the PbO3 trigonal pyramids units do exist in the whole glass forming composition range. Furthermore the existence of the first Pb–Pb correlation at ∼0.385 nm in the whole composition range suggests that the basic structural unit is considered to be a Pb2O4 unit, which consists of the edge-shared PbO3 trigonal pyramids. These results strongly imply that the Pb2O4 units participate in the glass network constructed by SiO4 tetrahedra even at low PbO content. Differing from other lead-containing glass systems, these structural characteristics of Pb ions in the PbO–SiO2 glass system are responsible for the extremely wide glass-forming region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1551-2916.2005.00297.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Structure and Nonlinear Optical Properties of Lanthanide Borate Glasses (1997)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 80 (1997), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The third–order nonlinear optical susceptibility, χ(3), of lanthanide (lanthanum, praseodymium, neodymium, and samarium) borate glasses has been measured by the third harmonic generation method. The structure of the present glass system has been studied by infrared and Raman spectroscopic methods. The network structures of the present Ln2O3–B2O3 glasses have been confirmed to be basically similar to each other. Praseodymium, neodymium, and samarium borate glasses exhibit χ(3) values that are larger than lanthanum borate glasses, because of the optical resonance effect, in accordance with the f–f transition. Especially, the χ(3) value for 30Pr2O3·70B2O3 glass is 1.8 × 10−12 esu, which is a factor of ∼60 larger than that of SiO2 glass. This striking enhancement of χ(3) is mainly attributed to the large transition moment to the first excitation state.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.1997.tb03210.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Preparation, Structure, and Properties of Thermally and Mechanically Improved Aluminum Titanate Ceramics Doped with Alkali Feldspar (2002)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 85 (2002), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Aluminum titanate (AT) ceramic materials doped with alkali feldspar ((Na0.6K0.4)AlSi3O8) have been prepared. These ceramics exhibited high sinterability, large resistance to thermal decomposition, and large flexure strength. The existence of liquid-phase feldspar at sintering temperatures promoted the formation of AT ceramics as the sintering agent. It was considered that silicon ions substituting for aluminum ions at the surface of AT crystal grains lowered the surface energy and hindered the diffusion of Ti4+ and Al3+, giving rise to the large resistance to thermal decomposition. As a result, doping with alkali feldspar was found to effectively improve the mechanical and thermal properties of AT ceramics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.2002.tb00573.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Correlation between Macro- and Microstructural Changes in Ge:SiO2 and SiO2 Glasses under Intense Ultraviolet Irradiation (2002)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 85 (2002), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The photochemical transformation mechanism of defects in germanosilicate and silica glasses under ultraviolet (UV) laser irradiation has been investigated based on the changes in Raman spectra before and after irradiation. Two types of silica glasses, fused silica (type I) and dry synthetic silica (type IV), and germanosilicate optical fiber preforms were irradiated by intense UV photons from excimer lasers. Spectral changes in optical absorption and Raman spectra were examined to clarify a correlation between the microscopic defect formation and the macroscopic structural changes causing a photorefractive effect. Successive generation of E′ centers through divalent centers is closely correlated with changes in Raman spectra, indicating that large structural changes in the glass network involved in this process would be the origin of photon-induced densification of the glasses. In addition, it has been proposed that the successive generation of E′ centers is mediated by transient divalent centers converted from relaxed cation homobondings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.2002.tb00227.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Structural Study of PbO–B2O3 Glasses by X-ray Diffraction and 11B MAS NMR Techniques (2000)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 83 (2000), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The structure of PbO–B2O3 glasses has been investigated in the composition range of 25–80 mol% PbO by using X-ray diffraction and 11B NMR techniques. The well-separated peaks due to Pb–O and Pb–Pb pairs were first observed in the radial distribution function, and peak deconvolution was performed by using a pair function method. The average coordination number of lead atoms was determined to be about 6 in the low-PbO-content region and about 3 in the high-PbO-content region. With an increase of PbO content, the peaks at 0.24 and 0.40 nm shifted to shorter distances, and especially the latter peak drastically increased in intensity in the composition range 〉50 mol% PbO. It was suggested that PbO is a main glass former in the high-PbO-content region. Based on the results obtained, we propose structural models of lead borate glasses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.2000.tb01588.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...