Accession Number : AD0409140

Title :   ATOMIC MOMENTS AND MAGNETIC COUPLING IN CATION EXCESSNICKEL ARSENIDES,

Corporate Author : MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB

Personal Author(s) : Goodenough,John B.

Report Date : 1963

Pagination or Media Count : 2

Abstract : The concept of a critical cation-cation separa tion R sub c, such that 3d electrons are collec tive if R<R sub c, are localized if R>R sub c, and the assumption that there is no discontinuity through R sub c in the interatomic electron correlations, which are known for R>R sub c from superexchange theory, permits interpretation of both the sign of the magnetic coupling and the magnitude of the observed magnetic moments in several cation-excess-nickel arsenides. It is necessary, however, to guess at the relative stabilities of a localized 3d level and the collective 3d states. This guess is qualitative ly reasonable and consistent with the idea that half-filled shells should be more stable than partially filled shells. Since the same physical arguments were used to account for the magnitudes of the atomic moments and the sign of the magnetic coupling in cubic transition elements and binary alloys, the exercise suggests that these physical ideas, though qualitative, have power to give considerable insight into the essential features of quite complex problems. (Author)

Descriptors :   (*ARSENIDES, MAGNETIC PROPERTIES), (*NICKEL COMPOUNDS, ATOMIC PROPERTIES), MOMENTS, ELECTRON DENSITY, MAGNETIC MOMENTS, STABILITY.

Distribution Statement : APPROVED FOR PUBLIC RELEASE