Association of Impurities and Vacancies in Copper Doped Potassium Tantalate Crystals Studied by EPR

The high temperature behavior of Electron Paramagnetic Resonance (EPR) signals of Cu2+ centers and Cu2+-Cu2+ exchanged coupled pair centers in potassium tantalate (KTaO3, and related K1 − xLixTa1 − yNbyO3) single crystals has been studied. EPR signals were observed in the range of 300–1000 K. The dynamic behavior of oxygen vacancies and the influence of its on Cu2+ ions EPR spectra were found. A model for divalent impurity ions in the potassium tantalate crystal is proposed.