FERROMAGNETISM OF MANGANESE COMPOUNDS

It is shown on the basis of the notion of a strong electron-electron i nteraction in the unit cell that a ferromagnetic instability is possib le in a system with hops between manganese cations and oxygen anions. The phase diagram for the existence of ferromagnetic ordering as a fun ction of the degrees of underfilling n(p) and n(i) of the 2p(6) shell of oxygen and the 3t(g)(6) shell of manganese, respectively, is constr ucted. (C) 1997 American Institute of Physics.