Positron lifetime study of the ferroelectric BaTiO3 in electric field

Abstract

BaTiO3, was studied by positron lifetime spectroscopy in static electric fioeld. The strength of the field was varied from 0 up to 104 V/cm. Two characteristic points were found at 4500 V/cm and at 8500 V/cm. These field strengths were related to subsequent ordering processes of the crystal. Additional temperaturee dependent measurements were perforrmed in the 70–310 range to confirn the interopretaion of the two positron lifetimes. The two expected phase transitions were observed and these measurements showd that positron are trapped by Ba vacancies.