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
    Magnetic properties of epitaxial (110) multilayer films of DyFe2 and YFe2 (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 6839-6841 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Laves phase DyFe2/YFe2 multilayers have been grown epitaxially on a YFe2 seed layer, with a (110) growth direction. Magnetic measurements taken in applied fields of up to 12 T, and from 5 K to room temperature, show that short period multilayers (∼100 Å) behave, collectively, as a single magnetic entity. As a result, it is possible to engineer magnetic compensation points, in a digital manner, by adjusting the thicknesses of the alternate DyFe2 and YFe2 layers. Nevertheless, the magnetic response of the DyFe2/YFe2 structure and that of the YFe2 seed layer are not completely independent of one another. Because of a mismatch in the Fe–Fe magnetic exchange at the multilayer/seed interface, a 180° magnetic soliton-like domain ("magnetic twister") is set up in the top of the YFe2 seed layer. A semiquantitative model describing the properties of the magnetic twister is presented and discussed. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.372859
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Spin configurations and negative coercivity in epitaxially grown DyFe2/YFe2 superlattices (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 6828-6830 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Molecular beam epitaxial methods have been used to grow single crystal Laves phase DyFe2/YFe2 superlattice samples with a (110) growth direction. In particular, the magnetic properties of the YFe2 dominated multilayer samples [wDyFe2/4wYFe2]×N with w=20, 30, 40, 45, 50, and 55 Å are presented and discussed. In principle, the multilayer films should possess similar magnetic properties because they are all nominally Dy0.2Y0.8Fe2. However, it is shown that their magnetic properties depend strongly on the thickness of the DyFe2 layers w. Those films with w≥45 Å possess negative coercivities, while those with w≤40 Å are positive. It is argued that this behavior can be understood in terms of a strong increase of the intrinsic coercivity of the DyFe2/YFe2 superlattice, taken as a whole, as w is reduced. For w≤40 Å almost none of the DyFe2 moments can be flipped over in the available field range (12 T). © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1359465
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Negative coercivity in epitaxially grown (110) DyFe2/YFe2 superlattices (2001)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 78 (2001), S. 964-966 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Molecular beam epitaxial methods have been used to grow single crystal Laves phase DyFe2/YFe2 superlattice samples with a (110) growth direction. Detailed magnetization curves have been obtained for YFe2 dominated multilayer samples [wDyFe2/4wYFe2]×16 with w=45, 50, and 55 Å. In particular, it is shown that the formation of magnetic exchange springs in the magnetically soft YFe2 layers, can be used to engineer multilayer samples with a negative coercivity. Further, by using asymmetric field cycling procedures, we have investigated the irreversible parts of the M–B loop, associated with the switching of the DyFe2 multilayers. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1344594
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Engineering coercivity in epitaxially grown (110) films of DyFe2–YFe2 superlattices (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 77 (2000), S. 573-575 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Molecular beam epitaxial methods have been used to grow single crystal Laves phase DyFe2–YFe2 superlattice samples with a (110) growth direction. It is shown that it is possible, in principle, to engineer a desired coercivity between the limits KDyFe2≤K≤∞. This can be achieved by adjusting the relative thickness of the individual DyFe2 and YFe2 layers, in multilayer films This novel feature is illustrated, using the superlattice films [x Å DyFe2/(100-x) Å YFe2]×40, with x=80, 60, 50, and 45. It is found that the measured coercivity is in semiquantitative agreement with a simple theoretical expression, for the nucleation fields in both bilayer and multilayer compounds. However, in practice, exchange spring penetration into the DyFe2 layers can set a limit to the maximum coercivity that can be achieved. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.127048
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Magnetic properties of a novel Pr-Fe-Ti phase : 38th Annual Conference on Magnetism an Magnetic Materials (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 7120-7121 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In a systematic study of the (Pr1−xTix)Fe5 alloy series, the (Pr0.65Ti0.35)Fe5 alloy has been found to have a dominant phase with either the rhombohedral Th2Zn17 structure or the newly discovered Nd2(Fe,Ti)19 (S. J. Collocott, R. K. Day, J. B. Dunlop, and R. L. Davis, in Proceedings of the Seventh International Symposium on Magnetic Anisotropy and Coercivity in R-T Alloys, Canberra, July 1992, p. 437) structure, depending on the annealing procedure. Powder-x-ray-diffraction patterns and scanning electron microscopy show that the sample annealed at a temperature of 850 °C followed by 1000 °C has the 2:17 structure whereas annealing at 1000 °C directly leads to the new 2:19 structure. Energy-dispersive x-ray analysis yields Pr:Fe:Ti ratios of 10.7:86.2:3.1 for the Pr2(Fe,Ti)17 phase and 9.2:85.9:4.9 for the Pr2(Fe,Ti)19 phase. 57Fe Mössbauer spectroscopy (at 295 K) gives values for the average 57Fe hyperfine field of 15.7 T for the 2:17 phase and 17.5 T for the 2:19 phase, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.356698
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Magnetic properties of Gd(Fe1−xCox)9Ti2 alloys : 38th Annual Conference on Magnetism an Magnetic Materials (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 7122-7124 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Four samples of Gd(Fe1−xCox)9Ti2 with x=0.0, 0.1, 0.2, and 0.3 were prepared by conventional arc melting followed by annealing at 1000 °C for 3 days. Powder-x-ray-diffraction patterns of these samples show that all of the samples have a dominant phase with the tetragonal CeMn6Ni5 structure. Traces of TiFe2 are also present. 57Fe Mössbauer spectra have been collected at 80 and 295 K. X-ray-diffraction patterns and Mössbauer spectra on magnetically aligned samples indicate that the easy axis of magnetization is the crystallographic c axis. The Curie temperature increases monotonically with increasing cobalt concentration. The average hyperfine field at 80 K reaches a maximum of 26.8(5) T for x≈0.2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.356699
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The easy magnetization directions in R6Fe23 intermetallic compounds: A crystal field analysis : The 41st annual conference on magnetism and magnetic materials (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 4186-4188 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: X-ray diffraction patterns on magnetically aligned powder samples of R6Fe23 (R=Dy, Er, Ho, and Tm) show that these compounds all magnetize along a [111] easy direction. At first sight it is difficult to reconcile the common easy magnetization direction of Er6Fe23 and Tm6Fe23 on one hand, with Dy6Fe23 and Ho6Fe23 on the other, since the respective B20 rare earth crystal field parameters of these pairs of compounds are opposite in sign. In this article we show that the crystal field stabilization energy of the [111] direction, relative to either [100] or [110], varies as the square of the crystal field term B20, thereby providing an explanation for the common [111] direction of easy magnetization. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.365115
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Effect of silver addition on superconductivity in the Bi1.6Pb0.4Sr1.6Ca2Cu3O10−y system (1990)
    Springer
    Journal of materials science 1 (1990), S. 30-33 
    Details
    ISSN: 1573-482X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Silver/superconductor composites containing 0 to 80 vol% silver have been prepared and their properties determined. Optimum heat treatment at sintering temperatures (∼ 800° C) under low oxygen pressures produces material with high critical current density and improves physical properties. Magnetic susceptibility measurements have been found to be consistent with resistivity results. In order to retain a single high-T c phase with increasing silver content, decreased oxygen partial pressures are required. Using the normal-state resistivity of these composites, a percolation threshold at a silver volume fraction of ∼43% was observed, while zero resistivity measurements show that a continuous superconducting network can be obtained with up to ∼80 vol% silver. The critical current density of 21 vol% silver-doped samples was found to be 1520 A cm−2 at 77.3 K, compared to 260 A cm−2 for an undoped sample.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00716013
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Analytical block-diagonalization of matrices using unit spherical tensors (1993)
    Springer
    Journal of mathematical chemistry 14 (1993), S. 391-403 
    Details
    ISSN: 1572-8897
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mathematics
    Notes: Abstract A new method for block-diagonalizing large Hamiltonian matrices, in closed form, is described. The method is based on (i) a general unitary transformation due to Slichter, and (ii) Fano's unit spherical operatorsÛ Q K (I i,I i). The method is illustrated with a simple three spin 1/2 dipolar coupled spin system, characterized by off-block-diagonal unit spherical tensorsÛ 0 2 (3/2,1/2,α) andÛ 0 2 (3/2,1 /2′,α). In addition, it is pointed out that any Hamiltonian matrix can be re-labelled in terms of fictitious spin labels, enabling a wide variety of unit spherical tensors to be used in block-diagonalization. For example, a single spin 5/2 matrix can be re-labelled using three spin labels 1/2, 1/2′, and 1/2″, respectively. Thus the tensor algebra required to block-diagonalize a 6 x 6 matrix is determined solely by the properties of the Pauli spin matrices. Finally, it is shown that re-labelling within the unit spherical tensor framework provides a unifying framework for standard basis operators, fictitious spin 1/2 and 1 operators, and others. The fictitious spin 1 / 2 unit spherical operators discussed in this paper differ from those of Vega and Pines.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01164478
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Irreducible half-integer rank unit spherical tensors (1994)
    Springer
    Journal of mathematical chemistry 15 (1994), S. 367-387 
    Details
    ISSN: 1572-8897
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mathematics
    Notes: Abstract A new class of half-integer rank spherical tensors is introduced. The motivation for investigating this new class of tensors originated from a desire to be able to partition matrices using mixtures of fictitious integer and half-integer spin labels. However, it is shown that they can also be used as annihilation/creation operators for spin-1/2, 3/2, etc., particles. In particular, half-integer rank tensors can be used to add/subtract a spin-1/2 particle from a given ensemble. Thus they can be viewed as the natural generalization of the raising and lowering operatorsI ±, in that they change bothI andM, simultaneously. The concept of a “universal rotator” is introduced and it is demonstrated that half-integer rank tensors obey the same contractional and rotational properties as their integer counterparts, but with half-integer rank. In addition, it is shown that half-integer rank tensors can be used to factorize the Pauli spin matrices. Finally, an example of the use of half-integer rank tensors in the block-diagonalization of a simple 3 x 3 matrix is presented and discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01277571
    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...