Accession Number:

AD0405550

Title:

THEORY OF INDIRECT EXCHANGE INTERACTIONS IN RARE ERTH METALS,

Descriptive Note:

Corporate Author:

MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB

Personal Author(s):

Report Date:

1962-09-11

Pagination or Media Count:

15.0

Abstract:

Liu has recently considered the effect of nonzero atomic orbital angular momentum on the exchange interactions between a localized magnetic moment and conduction electrons. By expanding a part of the band wave functions in spherical harmonics, He found that the leading term gave rise to the familiar scalar product interaction between conduction electron spin and total atomic angular momentum J. In the present paper, we derive Lius result by a simpler calculation, and obtain the first correction term in a similar expansion. Our main motivation in doing the latter is to investigate the validity of the common use of the leading term only, doubt being raised, a priori, by the fact that the Fermi wave vector times the radial extent of the 4f function is not 1. We then investigate, in second-order perturbation theory, the magnetic interaction between atoms n and m. The leading term is, of course, an isotropic Heisenberg-type interaction Anm O Jn.Jm corresponding to Lius result. The first correction term gives rise to anisotropic inter actions including pseudodipolar forces and an unconventional interaction which is quartic in the Js. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE