Investigation of the spin exchange interactions and magnetic structures of the CrVO₄-type transition metal phosphates, sulfates, and vanadates by spin dimer analysis

The CrVO₄-type magnetic oxides MM′O₄ consist of edge-sharing MO₄ octahedral chains condensed with M′O ₄ tetrahedra and exhibit a wide variety of magnetic structures. The magnetic properties of these oxides were examined by studying their spin exchange interactions on the basis of spin dimer analysis. The nature and magnitudes of the intra- and interchain spin exchange interactions depend on the square-to-rectangle distortion in the basal planes of the MO₄ chain and on the difference between the M 3d and O 2p orbital energies. The spiral magnetic structures of β-CrPO₄ and MnSO₄ originate from the pseudohexagonal arrangement of the MO₄ chains and the frustrated interchain antiferromagnetic interactions.