Band theoretical investigations within the local density approximation of the ferromagnetic silicides: UFe 10Si 2, UCo 10Si 2 and YFe 10Si 2

Abstract

The electronic and magnetic structures of the ferromagnetic silicides MT 10Si 2: UFe 10Si 2, UCo 10Si 2 and YFe 10Si 2 which crystallize in the ThMn 12-type structure are examined by use of scalar relativistic calculations based on the local density approximation. The magnetic role of uranium is addressed within the hypothetical alloy UFe 12. From the calculations including spin-orbit coupling effects, a positive orbital moment on U is found to partly compensate for the large negative spin-only moment with a resulting antiparallel spin alignment between U and Fe. In the MT 10Si 2 silicides, silicon acts as a stabilizing agent of the crystal structure through the hybridization between its s and p states and the s, p and d ones of T. For UFe 10Si 2 and YFe 10Si 2, the calculated magnetization and the trends of the evolution of the hyperfine fields are in fair agreement with experimental data.