Investigating Orbital Magnetic Moments in Spinel-Type MnV2O4 Using X-ray Magnetic Circular Dichroism

Element-specific magnetic structures, particularly orbital magnetic moments, of spinel-type MnV2O4 were investigated using X-ray magnetic circular dichroism (XMCD). X-ray absorption and XMCD spectra clearly reveal that the Mn2+ (d5) and V3+ (d2) states are coupled antiferromagnetically. Analyses of XMCD spectra using magneto optical sum rules revealed that small but finite orbital magnetic moments remain in both V and Mn 3d states, which accounts for the antiferro-type orbital ordering in the V sites of MnV2O4 with coexisting complex and real orbital states. Additionally, the Cr doping effect in MnV2O4 was examined. The XMCD spectra of Cr 3+ (d3) L-edges exhibited the substitution of Cr ions to the V sites ferromagnetically, with low conductivity through the suppression of the orbital ordering.