Correlation between electric magnetic transitions and electronic energy states near a Fermi level in spinel compounds Zn1−xCuxCr2Se4

Abstract The electronic states in Zn1−xCuxCr2Se4 have been studied by X-ray near edge absorption spectra (XANES) of K-edges of Zn2+, Cu1+, Cr3+ and Se2− ions. Ferromagnetism of the spinel compounds with x>0.10 are interpreted by a double exchange interaction between localized spins of Cr3+ ions and conductive Cr4+ spin polarons. The spin polaron is a triplet 3d orbital of 3dxy, 3dyz, and 3dzx, hybridized with spinless charge carriers (holes), which are induced in a top region of O 2p valence band by a substitution of Zn2+ with Cu1+ ions.