Determination of small bias fields in TGS using dielectric nonlinearities

Abstract

Dielectric nonlinearities in triglycine sulfate (TGS) have been measured by the analysis of harmonic components of the electric current, while a sinusoidal electric field was applied to the sample. From the nonlinear permittivities of second and third order in the paraelectric phase small bias fields can be evaluated. In the TGS sample a bias field in the order of 100 V/m with a temperature dependence according to a constant polarization of 8.5 μC/m² was found. This result can be explained by fixed dipolar defects.