Magnons in spin glasses: The high-field limit

1992 ◽  
Vol 46 (1) ◽  
pp. 223-230 ◽  
Author(s):  
I. Avgin ◽  
D. L. Huber ◽  
W. Y. Ching
Keyword(s):  
1993 ◽  
Vol 48 (21) ◽  
pp. 16109-16112 ◽  
Author(s):  
I. Avgin ◽  
D. L. Huber ◽  
W. Y. Ching

1998 ◽  
Vol 51 (2) ◽  
pp. 349 ◽  
Author(s):  
J. Bogner ◽  
H. Schachner ◽  
M. Reissner ◽  
W. Steiner

The strong dynamics of magnetic correlations are observed by high field 57Fe Mössbauer investigations for the spin glasses AuFe and Y(Fe, Al)2 in the temperature interval between the freezing temperature Tf and approximately 7 to 10Tf. All recorded spectra can be analysed with a model which takes into account these dynamics by allowing the formation of correlated states after a stochastically varying time τoff and their decay after a time τon, restricting the number of subspectra to the different number of Fe atoms in the first neighbour shell. Whereas for the different Fe environments, in addition to centre shift and quadrupole splitting, different hyperfine fields of the two stochastically formed states can always be resolved, the same set of τon and τoff values was obtained for all subspectra above approximately 4Tf. The external field hinders the decay of the correlated regions. The temperature dependence of ¿ on scales with Tf and exhibits a power law with exponents of –2 for the Fe-rich and –1 for the Fe-poor compounds.


1960 ◽  
Vol 38 (7) ◽  
pp. 941-944 ◽  
Author(s):  
Richard Stevenson

Magneto-optical rotation by transmission through or reflection from solids is examined by the classical free electron theory, with the view of taking such a measurement using fields in the megagauss range. In general the rotation is a markedly non-linear function of the magnetic field, and in some cases can change in sign as the field increases. For very low fields the rotation varies directly with B, but in the high field limit the rotation varies inversely with the field. For substances in which the intercollision time of the electron is small, measurements of the Kerr rotation (i.e. by reflection) will give the electron mobility as a function of the magnetic field, and thus will give important data which can be used in conjunction with high field magnetoresistance experiments.


1993 ◽  
Vol 07 (01n03) ◽  
pp. 993-996
Author(s):  
YOSHIRO KAKEHASHI

The reentrant spin glasses (RSG) in amorphous transition metals are examined on the basis of the finite-temperature theory of amorphous metallic magnetism. It is shown that a competition between the short-range ferromagnetic couplings and the long-range antiferromagnetic couplings forms the itinerant-electron RSG via the structural disorder characteristic to the amorphous pure metals. Calculated high-field susceptibilities, forced volume magnetostriction, and T-p phase diagram explain well the experimental data of Fe-rich amorphous alloys around 90 at.% Fe. This supports that the RSG around 90 at.% Fe in Fe-rich amorphous alloys are dominated by the structural disorder.


2001 ◽  
Vol 11 (08) ◽  
pp. 1457-1468 ◽  
Author(s):  
LUIS L. BONILLA ◽  
JUAN S. SOLER

A reduced drift-diffusion (Smoluchowski–Poisson) equation is found for the electric charge in the high-field limit of the Vlasov–Poisson–Fokker–Planck system, both in one and three dimensions. The corresponding electric field satisfies a Burgers equation. Three methods are compared in the one-dimensional case: Hilbert expansion, Chapman–Enskog procedure and closure of the hierarchy of equations for the moments of the probability density. Of these methods, only the Chapman–Enskog method is able to systematically yield reduced equations containing terms of different order.


Sign in / Sign up

Export Citation Format

Share Document