Investigation of I-V characteristics in polycrystalline BaTiO3

Polarisation currents were investigated in polycrystalline BaTiO3in order to investigate its I-V characteristics. All but one of the measurements were performed at temperatures below the Curie point, for voltages between 1 V and 1000 V. The experimental curves consist of three parts of different shape: a region in which Ohm's law is valid, a region in agreement with the Fridkin-Kreher theory and a region showing a rapid increase in current for the highest applied fields. Comparison of the SCLC theory for ferroelectrics with the results obtained allows an estimate to be made of the temperature dependence of the carrier mobility in the sample. It increases from 10-8cm V-1s-1at 25 degrees C to 10-5cm V-1s-1at 140 degrees C.