Ferromagnetism of manganese compounds

Abstract

It is shown on the basis of the notion of a strong electron-electron interaction in the unit cell that a ferromagnetic instability is possible in a system with hops between manganese cations and oxygen anions. The phase diagram for the existence of ferromagnetic ordering as a function of the degrees of underfilling np and nt of the 2p6 shell of oxygen and the 3tg6 shell of manganese, respectively, is constructed.