Single Crystal Growth of Ilmenite-Type MnVO3 by Solid-State Recrystallization

We successfully obtained high-quality single-domain crystals of ilmenite-type MnVO3 under high-pressure and high-temperature conditions (4 GPa and 1173 K for 1-8 h). The maximum crystal size was similar to 0.5 mm. Single crystals were grown by solid-state recrystallization near the perovskite-ilmenite phase boundary under high-pressure conditions. Crystal growth occurred without fluxes or water, unlike conventional single crystal growth by high-pressure synthesis methods. Crystal structure refinement revealed that V-V dimers, produced by direct chemical bonding between vanadium ions, existed below 550 K at ambient pressure. The V-V dimerization was accompanied by a structural phase transition from rhombohedral to triclinic ilmenite-type structures. The obtained single crystals can facilitate precise analyses using resonant inelastic X-ray scattering and angle-resolved photoemission spectroscopy, which can reveal the mechanism underlying the phenomenon of V-V dimerization.