Study on a nonlinear antiferroelectric capacitor

To develop high energy storage density capacitors for various fields, such as primary energy systems for fusion facilities, antiferroelectric, a type of perspective dielectric, was studied in this article. The relationship of electric displacement and electric field of antiferroelectric is nonlinear and has the property of hysteresis loop. Because of the sharp increasing of dielectric constant near the switching field, antiferroelectric is a type of potential high energy storage density material. Thus, a sample of antiferroelectric capacitor was made and its discharging property was studied. On account of the nonlinearity of antiferroelectric capacitor, the discharging current of LRC circuit in under-damping situation is not a strict equivalent periodic sine wave. The periods of discharging current decrease in the discharging process. In addition, under different charging voltage, the periods are quite different, which indicates the changing of capacitance. The capacitance of first half period under 0.86 and 2.98 kV is 2619 and 3013 pF, respectively. All these properties make antiferroelectric a type of potential dielectric with high energy storage density and tunability.