Abstract
Ac conductivity and dielectric losses are measured on a sodium aluminosilicate glass using various experimental conditions. Data obtained using metallic contacts and insulating barriers are compared. The influences of the thermal environment, i.e. iso versus non-isothermal, and of the application of a constant dc electric field, i.e. BIAS, are also investigated. It is thus shown that the use of non-isothermal conditions and insulating barriers is a convenient tool for extracting and hence for analyzing the bulk intrinsic polarization response of the sample. The analysis of this response with a simple model based on distribution of energy barriers gives some insights into the glass structure which turns out to be rather homogeneous