Electronic structures and magnetic moments of Fe3+ySi1-y and Fe3-xVxSi alloys with DO3-derived structure.

Kudrnovsky J., Christensen N.E., Andersen O.K.

The authors present ab initio calculations of magnetic moments and local electronic densities of states in binary Fe3+ySi1-y and ternary Fe3-xVxSi random alloys with DO3-derived structures. The local-spin-density approximation, the linear muffin-tin orbital method, and the coherent-potential approximation (LMTO-CPA) were used. In Fe3+ySi1-y the excess (as compared to Fe3Si) Fe atoms occupy the Si(D) sites of the Fe3Si host and create a strong d scattering. A realistic-alloy calculation thus requires the application of the CPA. In both types of alloys the moments of Fe atoms occupying the B sites remain essentially unchanged when the concentrations (y in Fe3+ySi1-y, x in Fe3-xVxSi) are varied. The Fe(A,C) moments vary almost linearly with y and x, in agreement with experimental observations. The sublattice density-of-states functions provide insight into the site preference for substitutional transition-metal impurities in Fe3Si.

Physical Review B, 43 5924-33, 1991.

Max-Planck Institut für Festkörperforschung;
Postfach 80 06 65   D-70506 Stuttgart