Soft x-ray magnetic circular dichroism study of valence and spin states in FeT₂O₄ (T = V, Cr) spinel oxides

Electronic structures of spinel oxides FeT₂O₄ (T = V, Cr) have been investigated by employing soft x-ray magnetic circular dichroism (XMCD) and soft x-ray absorption spectroscopy (XAS). XAS reveals that Cr and V ions are trivalent, and that Fe ions are nearly divalent in FeT ₂O₄ (T = V, Cr). Finite XMCD signals are observed in FeV₂O₄ at T 80 K, while they are very weak in FeCr ₂O₄. XMCD shows that Fe spins are antiparallel to V and Cr spins, with the V and Cr spins being canted from Fe spins, which suggests a Yafet-Kittel type triangular spin configuration in FeT₂O₄ (T = V, Cr).