Production and Properties of Europium Polytantalate Single Crystals

摘要

Europium polytantalate was first observed (when investigating an Eu_2O_3-Ta_2O_5 system [1,2]) as a phase that is characterized by a narrow homogeneity range of 11-16 mol% Ta_2O_5 and undergoes peritectoid transformation into α-Ta_2O_5 and EuTa_3O_9 phases in the temperature range 1623-1673 K. Its X-ray and luminescence properties were examined with polycrystalline samples. As a result, this material was proposed as a red-glow luminophor [3]. Later, it was established that the polytantalate composition corresponds to the formula EuTa_7O_(19) [4].