title: Highly stable cooperative distortion in a weak Jahn-Teller d2 cation: perovskite-type ScVO3 obtained by high-pressure and high-temperature transformation from bixbyite.
abstract: A novel ScVO(3) perovskite phase has been synthesized at 8 GPa and 1073 K from the cation-disordered bixbyite-type ScVO(3). The new perovskite has orthorhombic symmetry at room temperature, space group Pnma, and lattice parameters a = 5.4006(2) Å, b = 7.5011(2) Å, and c = 5.0706(1) Å with Sc(3+) and V(3+) ions fully ordered on the A and B sites of the perovskite cell. The vanadium oxygen octahedra [V-O(6)] display cooperative Jahn-Teller (JT) type distortions, with predominance of the tetragonal Q(3) over the orthorhombic Q(2) JT modes. The orthorhombic perovskite shows Arrhenius-type electrical conductivity and undergoes a transition to triclinic symmetry space group P-1 close to 90 K. Below 60 K, the magnetic moments of the 4 nonequivalent vanadium ions undergo magnetic long-range ordering, resulting in a magnetic superstructure of the perovskite cell with propagation vector (0.5, 0, 0.5). The magnetic moments are confined to the xz plane and establish a close to zigzag antiferromagnetic mode.
authors.affiliation: Departamento de Química Inorgánica & Laboratorio Complutense de Altas Presiones, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain. ilaisza@hotmail.com
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Castillo-Martínez
authors.forename: Mario
authors.initials: M
authors.lastname: Bieringer
authors.forename: Shahid P
authors.initials: SP
authors.lastname: Shafi
authors.forename: Lachlan M D
authors.initials: LM
authors.lastname: Cranswick
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Alario-Franco