High-pressure ilmenite-type MnVO3: crystal and spin structures in the itinerant-localized regimes

Abstract

Herein we report the Peierls-like transition in the high-pressure ilmenite-type MnVO3. The first-order structural transition from a low-temperature P[1 with combining macron] to a high-temperature R[3 with combining macron] occurs at 475 K, accompanied by a semiconductor to metal-like transition. The triclinic distorted phase presents a V–V dimerization with a short ∼2.85 Å bond formation at 300 K. Below 80 K MnVO3 orders antiferromagnetically with a small ferromagnetic component. Neutron diffraction reveals that both Mn and V cations contribute to the magnetic ordering, contrary to what expected on the V–V dimer formed. Extended Hückel and DFT calculations expose that the formation of covalent pairing is only partially achieved, contrary to the MgVO3 and CoVO3 counterparts.