Structure, Luminescence, and Transport Properties of EuVO4

Metastable scheelite EuVO4 was stabilized by a high temperature and pressure method, which was transformed into a stable zircon phase by annealing treatment in air. Scheelite EuVO4 gave strong emissions with a dominant peak at 617 nm associated with the D0F2 transition of Eu . Eu Mössbauer spectra indicated that the isomer shift for the metastable scheelite phase was ca. 0.5 mm/s lower than that for the zircon phase, which was ascribed to a reduced covalency in the Eu-O bond originated via a charge transfer from oxygen to Eu in scheelite lattice by producing an enhanced shielding of 4f electrons on the s orbital as well as a decrease in s electron density around Eu nucleus. Impedance spectra for the zircon phase clearly demonstrated an ionic hopping in the bulk with a conductivity of ca. 1.0 3 10 S cm at 500°C. EuVO4 is proved to be both a potential phosphor and a potential ionic conductor. © 2001 The Electrochemical Society. @DOI: 10.1149/1.1388633# All rights reserved.