Highly Stable Cooperative Distortion in a Weak Jahn–Teller d2 Cation: Perovskite-Type ScVO3 Obtained by High-Pressure and High-Temperature Transformation from Bixbyite

A novel ScVO3 perovskite phase has been synthesized at 8 GPa and 1073 K from the cation-disordered bixbyite-type ScVO3. 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 Sc3+ and V3+ ions fully ordered on the A and B sites of the perovskite cell. The vanadium oxygen octahedra [V–O6] display cooperative Jahn–Teller (JT) type distortions, with predominance of the tetragonal Q3 over the orthorhombic Q2 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.