Antiferroelectric Ceramics with Field-Enforced Transitions: A New Nonlinear Circuit Element

Ceramic dielectrics capable of field-enforced antiferroelectric-to-ferroelectric transitions from below -60°C to over 100°C have been made. The transition manifests itself by a D/E hysteresis figure with a linear central region and loops showing saturation on either end. Previously studied materials have exhibited this phenomenon only in a very limited temperature range. Conditions for obtaining the effect over a wide temperature range are: 1) a polymorphic inversion from ferroelectric to antiferroelectric with ascending temperature, and 2) a relatively high-peak dielectric constant at the antiferroelectric-paraelectric transition temperatures. Nonlinear capacitance, usefulness for capacitive energy storage, and novel transducer properties are described.