title: New polymorph of InVO4: a high-pressure structure with six-coordinated vanadium.
abstract: A new wolframite-type polymorph of InVO4 is identified under compression near 7 GPa by in situ high-pressure (HP) X-ray diffraction (XRD) and Raman spectroscopic investigations on the stable orthorhombic InVO4. The structural transition is accompanied by a large volume collapse (ΔV/V = -14%) and a drastic increase in bulk modulus (from 69 to 168 GPa). Both techniques also show the existence of a third phase coexisting with the low- and high-pressure phases in a limited pressure range close to the transition pressure. XRD studies revealed a highly anisotropic compression in orthorhombic InVO4. In addition, the compressibility becomes nonlinear in the HP polymorph. The volume collapse in the lattice is related to an increase of the polyhedral coordination around the vanadium atoms. The transformation is not fully reversible. The drastic change in the polyhedral arrangement observed at the transition is indicative of a reconstructive phase transformation. The HP phase here found is the only modification of InVO4 reported to date with 6-fold coordinated vanadium atoms. Finally, Raman frequencies and pressure coefficients in the low- and high-pressure phases of InVO4 are reported.
authors.affiliation: Departamento de Física Aplicada-ICMUV, Universidad de Valencia, MALTA Consolider Team, Edificio de Investigación , C/Dr. Moliner 50, 46100 Burjassot, Valencia, Spain.
authors.forename: Daniel
authors.initials: D
authors.lastname: Errandonea
authors.forename: Oscar
authors.initials: O
authors.lastname: Gomis
authors.forename: Braulio
authors.initials: B
authors.lastname: García-Domene
authors.forename: Julio
authors.initials: J
authors.lastname: Pellicer-Porres
authors.forename: Vasundhara
authors.initials: V
authors.lastname: Katari
authors.forename: S Nagabhusan
authors.initials: SN
authors.lastname: Achary
authors.forename: Avesh K
authors.initials: AK
authors.lastname: Tyagi
authors.forename: Catalin
authors.initials: C
authors.lastname: Popescu