Modeling of dynamic ferroelectric hysteresis loops in purified Rb2ZnCl4

Abstract

Dynamic hysteresis loops were recorded in the ferroelectric lock-in phase of purified Rb2ZnCl4 crystals at a temperature T=188 K which is 5 K below the incommensurate–commensurate phase transition. The hysteresis loops observed in the frequency range 50 Hz<f<5 kHz can quantitatively be described by a model that treats a sideways shift of planar, nearly regular arranged domain walls as the only mechanism of polarization reversal in Rb2ZnCl4. Due to defect interaction, the velocity v of the domain wall depends nonlinearly on the effective force F acting on it and a scaling behavior v∼(F−Fc)θ with θ=1.45 is observed.