Электронная структура и магнитная восприимчивость сплавов Fe1-xCoxSi

Abstract

Ab initio calculations of the electronic structure of Fe1-xCoxSi alloys have been supple-mented with the consideration of fluctuations of the spin density of collective d electrons with the Hubbard interactions at Fe and Co atoms randomly distributed over sites. The magnetic-state equation in the developed model describes helicoidal ferromagnetism and its disappear-ance accompanied by the occurrence of a maximum of magnetic susceptibility at temperature TC and spin helix fluctuations at T>TC.