title: A new, layered monoclinic phase of Co3O4 at high pressure.
abstract: We present the crystal structures and electronic properties of a Co3O4 spinel under high pressure. Co3O4 undergoes a first-order transition from a cubic (CB) Fd3̄m to a lower-symmetry monoclinic (MC) P21/c phase at 35 GPa, occurring after the local high-spin to low-spin phase transition. The high-pressure phase exhibits the octahedral coordination of Co(II) and Co(III), whereas the CB phase contains the fourfold coordination of Co(II) and the sixfold coordination of Co(III). The CB-to-MC transition is attributed to the charge-transfer between the di- and trivalent cations via the enhanced 3d-3d interactions.
authors.affiliation: Materials Theory Division, Department of Physics and Astronomy, Uppsala University, P.O. Box 530, S75121, Uppsala, Sweden. wei.luo@physics.uu.se.
authors.forename: Thanayut
authors.initials: T
authors.lastname: Kaewmaraya
authors.forename: Wei
authors.initials: W
authors.lastname: Luo
authors.forename: Xiao
authors.initials: X
authors.lastname: Yang
authors.forename: Puspamitra
authors.initials: P
authors.lastname: Panigrahi
authors.forename: Rajeev
authors.initials: R
authors.lastname: Ahuja