ELECTRONIC AND MAGNETIC-STRUCTURE OF TERNARY TRANSITION-METAL ARSENIDES RELATED TO THE FE2X TYPE (X = P, AS)

The spin-polarized KKR-CPA band structure calculations were done by KK R-CPA method on Mn2-xCrxAs series [both in ferromagnetic (FM) and anti -ferromagnetic (AFM) state], guided by the neutron diffraction measure ments on CrMnAs. Our results show a specific evolution of the electron ic structure. Going from AFM Mn2As to AFM CrMnAs, we found that the ma gnetic moments on Cr-atoms change a sign, crossing zero-value near x a pproximate to 0.5. For the hexagonal CrNiAs compound, the present KKR results, reveal a significant effect of lattice parameters on magnetic properties. Computed a and c lattice constants by minimizing total en ergy are 2-3% smaller than found in a new neutron diffraction experime nt (at T=117 K). Generally, our computations of the magnetic moments a re in quite good agreement with values deduced from neutron data. (C) 1997 Elsevier Science S.A.