V-V Dimerization and Magnetic State of Cobalt Ions in Ilmenite-Type CoVO 3 .

The nature of chemical bonds determines the electronic and magnetic properties of compounds. A metal-metal bonding (V-V dimer) and its effect on the magnetism of ilmenite-type CoVO 3 were studied. Polycrystalline CoVO 3 samples were synthesized using a high-pressure synthesis method. Crystal structure refinement revealed that V-V dimers exist at temperatures below 550 K in the vanadium layers. Co 2+ in CoVO 3 exhibits an S = 3/2 state, whereas a J eff = 1/2 state was reported in ilmenite-type CoTiO 3 . The existence of V-V dimers reduces the structural symmetry (from R 3 to P 1), which can change the magnetic ground state.