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
    Light scattering from nonequilibrium concentration fluctuations in a polymer solution (2000)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 112 (2000), S. 9139-9150 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We have performed light-scattering measurements in dilute and semidilute polymer solutions of polystyrene in toluene when subjected to stationary temperature gradients. Five solutions with concentrations below and one solution with a concentration above the overlap concentration were investigated. The experiments confirm the presence of long-range nonequilibrium concentration fluctuations which are proportional to (∇T)2/k4, where ∇T is the applied temperature gradient and k is the wave number of the fluctuations. In addition, we demonstrate that the strength of the nonequilibrium concentration fluctuations, observed in the dilute and semidilute solution regime, agrees with theoretical values calculated from fluctuating hydrodynamics. Further theoretical and experimental work will be needed to understand nonequilibrium fluctuations in polymer solutions at higher concentrations. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.481524
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Training effect of exchange biased iron–oxide/ferromagnet systems (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 6910-6912 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Substantial training effect in hysteresis loops was observed in ferromagnet (F)–antiferromagnet (AF) exchange coupled systems of the structure, Si(100)/iron–oxide(tAF)/F layer (5 nm)/Ta(10 nm), prepared by magnetron sputtering. The exchange bias field and the coercivity decrease with increasing number of loop cycles. The initially asymmetric hysteresis loop becomes more symmetric as the number of loop cycles increases. The effect is more prominent in the descending curve starting from the saturation in the positive (parallel to the pinned direction) direction than in the ascending curve of the hysteresis loop. The value of the ascending curve switching field |Hsw+| is rather unchanged while the switching field |Hsw−| in the descending curve decreases drastically with repeated hysteresis loop cycling as was observed in some CoO/Co and NiO/NiFe systems. Those phenomena can be interpreted by a modification of the extended model of Fulcomer and Charap's: the essential modification being the introduction of positive and negative exchange coupling between AF grains. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1360682
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Biquadratic coupling effect on magnetoresistance response curves of spin valves with a synthetic antiferromagnet (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 6814-6816 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Both normal and inverse magnetoresistance (MR) response curves were observed for synthetic spin valves with the structure of Si(100)/Ru/Co(t1)/Ru(0.7 nm)/Co(t2)/Cu(3 nm)/Co(t3)/Ru. Under the assumption of a coherent rotation of the magnetization in the three Co layers, the hysteresis loops, magnetization response, and MR response curves were calculated as a function of the parameters of the system. The parameters include antiferromagnetic coupling of Co(t1) and Co(t2) through Ru layer, a weak ferromagnetic coupling of Co(t2) and Co(t3) through Cu spacer, giant magnetoresistance of the Co/Cu/Co and Co/Ru/Co systems, and AMR contribution of each Co layer. The uniaxial anisotropy of each Co layer and a distribution of the coupling strength of Co(t1)/Ru/Co(t2) were also included. To fit the experimental data well, it was necessary to include a biquadratic coupling in the Co(t1)/Ru/Co(t2) trilayer. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1360679
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Rotational hysteresis of torque curves in polycrystalline ferro/antiferromagnetic systems (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 7546-7548 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Rotational hysteresis of ferromagnetic (F)/antiferromagnetic (AF) exchange coupled systems was studied by using NiFe/IrMn, NiFe/FeMn, and NiFe/NiMn samples sputter deposited under almost the same conditions, although the sample of NiFe/NiMn was annealed later to obtain the antiferromagnetic phase for the NiMn layer. The rotational hysteresis of each sample exhibited quite a different feature from each other, especially in the rotational hysteresis–magnetization angle curves. The NiFe/IrMn bilayer showed a dip at around the antiparallel direction to the applied field direction during sample preparation (pinning direction), while the NiFe/NiMn bilayer exhibited a large peak in that direction. The NiFe/FeMn bilayer did not show any noticeable structure in the rotational hysteresis–magnetization curve. Based on the analysis of those data done by using the model recently proposed by the authors, the following was inferred: (1) The distribution of the anisotropy easy axes of IrMn of the NiFe/IrMn bilayer grains is limited in some range of angles around the pinning direction. Some direct exchange coupling exists between the IrMn grains. (2) The distribution of the anisotropy easy axes of FeMn grains of the NiFe/FeMn bilayer is almost random and the direct exchange coupling between the FeMn grains is negligible. (3) In the NiFe/NiMn bilayer, substantial strength of direct exchange coupling exists between some of the grains which switch and the ones which do not switch with the rotation of the magnetization of the NiFe layer, although the volume fraction of the former is much smaller than the latter. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1358833
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Crystallization kinetics of amorphous Sm8Fe85Si2C5 alloy (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 496-499 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The crystallization kinetics of amorphous Sm8Fe85Si2C5 alloy has been investigated. As the alloy is heated to 900 °C, the crystalline phases of the alloy are composed of α-Fe phase and Sm2(Fe, Si)17Cx. At the beginning of crystallization the activation energy of the α-Fe phase is about 425 kJ/mol, it remains relatively constant as the crystallized fraction of the α-Fe phase is below 70%, and then it declines with increasing the crystallized fraction. When the crystallized fraction of the Sm2(Fe, Si)17Cx is below 50%, the activation energy of crystallization of the phase remains between 518 and 530 kJ/mol, and then decreases with the crystallized fraction. The crystallization behavior of the α-Fe phase and Sm2(Fe, Si)17Cx essentially results in the formation of an α-Fe/Sm2(Fe, Si)17Cx composite microstructure with a coarse grain size in annealed Sm8Fe85Si2C5 alloy, which is attributed to a difficult nucleation and an easy growth for both the α-Fe phase and Sm2(Fe, Si)17Cx in the alloy. Cu and Nb can be used to change the crystallization behavior of the α-Fe phase in the amorphous Sm8Fe85Si2C5 alloy, which is helpful to the formation of the α-Fe/Sm2(Fe, Si)17Cx nanocomposite microstructure with a fine grain size for the α-Fe phase in the alloy. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1330769
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Ordering and shape of self-assembled InAs quantum dots on GaAs(001) (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 76 (2000), S. 2229-2231 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Quantitative grazing-incidence small-angle x-ray scattering experiments have been performed on self-assembled InAs quantum dots (QDs) grown by molecular-beam epitaxy. We find pronounced nonspecular diffuse scattering satellite peaks with high diffraction orders, indicating a lateral ordering in the spatial positions of the InAs QDs. The mean-dot–dot distance and correlation lengths of the dot lateral distribution are found to be anisotropic. We observe the sharpest dot distribution in the [110] direction. Additional broad diffraction peaks are observed and associated with dot facet crystal truncation rods of the {111} and {101} facet families. This suggests an octagonal-based dot shape. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.126305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Strain status of self-assembled InAs quantum dots (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 77 (2000), S. 1295-1297 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Grazing incidence x-ray diffraction experiments employing the asymmetric (202) Bragg diffraction have been performed to characterize self-assembled InAs quantum dots grown by molecular-beam epitaxy. We find that the strain is elastically relaxed with different components. The volume distribution of partially strained InAs inside islands is peaked at intermediate strain values. The fraction of both almost fully strained and totally relaxed InAs is found to be small. In addition, a small volume fraction of relaxed InxGa1−xAs is found. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1290152
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Structural origin of coercivity enhancement and exchange-bias field in double antiferromagnet/ferromagnet bilayers (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 76 (2000), S. 3974-3976 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: An experimental method to identify the structural origins of the coercivity enhancement and the exchange-bias field of polycrystalline ferro-antiferromagnetic (F/AF) coupled systems is proposed. The exchange-bias field and the coercivity of the FI layer of the samples of the structure FI/AFI are compared with those of the FII layer of the samples of the structure FII/AFII/FIII/AFIII. It is concluded that, for a given temperature, it is those AF grains which stop their growth at a critical thickness that contribute to the coercivity enhancement, and those which grow over the critical thickness that contribute to the exchange-bias field. Meanwhile the effective magnetic surface anisotropy introduced to the top surface of the AFII layer by the FIII layer can increase the exchange-bias field of the FII layer when the AFII layer is thin. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.126839
    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...