Dielectric Breakdown of Single-Crystal Strontium Titanate

Measurements of the intrinsic dielectric breakdown strength of single-crystal strontium titanate over a temperature range from -195° to + 100°C and under both pulse and dc conditions are described; dc breakdown at + 100°C is thermal in origin. At room temperature and at -40°C the breakdown strength is independent of duration of applied field and of sample configuration and hence may properly be termed intrinsic. At -80° and -195°C, both the values of breakdown strength and the scatter of the data depend strongly on sample configuration. The breakdown strength unexpectedly decreases with increasing temperature. Current-voltage curves show an anomalous saturation effect at low temperature. These effects may be qualitatively explained by postulating that the high electrostrictive stress causes the creation of electron trapping centers.