title: Structural properties of PbVO3 perovskites under hydrostatic pressure conditions up to 10.6 GPa.
abstract: High-pressure synchrotron x-ray powder diffraction experiments were performed on PbVO(3) tetragonal perovskite in a diamond anvil cell under hydrostatic pressures of up to 10.6 GPa at room temperature. The compression behavior of the PbVO(3) tetragonal phase is highly anisotropic, with the c-axis being the soft direction. A reversible tetragonal to cubic perovskite structural phase transition was observed between 2.7 and 6.4 GPa in compression and below 2.2 GPa in decompression. This transition was accompanied by a large volume collapse of 10.6% at 2.7 GPa, which was mainly due to electronic structural changes of the V(4+) ion. The polar pyramidal coordination of the V(4+) ion in the tetragonal phase changed to an isotropic octahedral coordination in the cubic phase. Fitting the observed P-V data using the Birch-Murnaghan equation of state with a fixed [Formula: see text] of 4 yielded a bulk modulus K(0) = 61(2) GPa and a volume V(0) = 67.4(1) Å(3) for the tetragonal phase, and the values of K(0) = 155(3) GPa and V(0) = 58.67(4) Å(3) for the cubic phase. The first-principles calculated results were in good agreement with our experiments.
authors.affiliation: Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.forename: Dayong
authors.initials: D
authors.lastname: Tan
authors.forename: Wansheng
authors.initials: W
authors.lastname: Xiao
authors.forename: Maoshuang
authors.initials: M
authors.lastname: Song
authors.forename: Ming
authors.initials: M
authors.lastname: Chen
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Xiong
authors.forename: Jian
authors.initials: J
authors.lastname: Xu