Accession Number : AD0716799

Title :   Localized Spin Fluctuations in Metals,

Corporate Author : PENNSYLVANIA UNIV PHILADELPHIA DEPT OF PHYSICS

Personal Author(s) : Schrieffer,J. R. ; Evenson,W. E. ; Wang,S. Q.

Report Date : 1970

Pagination or Media Count : 33

Abstract : The concepts and results of several theories of localized spin fluctuations are contrasted. The random phase approximation--qualitatively correct for weak exchange coupling U--overemphasizes the collective nature of the fluctuations and in dilute alloys leads to an unphysical instability for U = or > U sub c. For U approximately equal to U sub c, nonlinear interactions between spin fluctuations suppress the instability. These anharmonic effects have been treated through the functional average and the diagram summation schemes, and they lead to a smooth variation of the system properties as U increases through U sub c. A complementary treatment in which one studies the time-evolution of spin fluctuations is also considered. (Author)

Descriptors :   (*FERROMAGNETISM, SOLID STATE PHYSICS), MAGNETIC MOMENTS, HARTREE-FOCK APPROXIMATION, ANTIFERROMAGNETISM, INTERACTIONS, IMPURITIES

Subject Categories : Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE