Synthesis of a new compound in the La-Cu-V-O system: La 3Cu 2VO 9

Abstract

A new quaternary compound, La 3Cu 2VO 9, was synthesized and studied by XRD, TEM and EDS. The phase was found to be stoichiometric and stable in air up 1000 °C. From powder XRD data the crystalline phase could be described by a hexagonal unit cell, with the parameters a h= 14.4427(7) A ̊ , c h= 10.685(1) A ̊ and cell volume of 1930.15 Å 3. Electron diffraction studies yielded a 4 times larger monoclinic supercell with the parameters a m = 14.4427 A ̊ , b m = 10.685 A ̊ , c m= 52.07 A ̊ , and β = 106.1 ° . The valence states of Cu and V are discussed with respect to conducting and catalytic properties.