Investigation on frequency-dependent hysteresis loops of ferroelectric materials

Abstract

In this paper, a frequency-dependent theory is developed to study the polarization hysteresis loops of ferroelectric materials. From experimental observations, the polarization hysteresis loops strongly depend on the electric field loading frequency. When the frequency increases both remanent polarization and coercive electric field are increasing, while the dielectric constant remains unchanged at the given range of the frequency. An exponential function is introduced to express such frequency-dependent changes of the remanent polarization and the coercive field. Then a micromechanics-based approach can be applied to study hysteresis loops of ferroelectrics. To verify the developed theory, we first compare the results between the theoretical calculations and experimental data of PZT. Then we applied the model to study the frequency effects on hysteresis loops of a complex ceramic BaMn3Ti4O14.25 (BMT-134) under the electric field.