Dielectric dispersion associated with the dc-electric-field-enforced ferroelectric phase transition in the pressure-induced antiferroelectric CsH2PO4.

Abstract

The dc-electric-field dependence of the dielectric properties (complex permittivity and relaxation time) of the antiferroelectric ${\mathrm{CsH}}_{2}$${\mathrm{PO}}_{4}$ was investigated at 4.5 kbar under various frequencies. The strong dielectric dispersion along the b axis associated with the field-enforced ferroelectric phase transition was observed. The slowing down of the relaxation time toward a critical electric field ${\mathit{E}}_{\mathrm{cr}}$, which induces the forced transition to the ferroelectric phase, was observed. Although the dielectric dispersion strength is zero without an applied dc field ${\mathit{E}}_{\mathit{d}}$, with an increase in ${\mathit{E}}_{\mathit{d}}$ it increases gradually, rapidly near ${\mathit{E}}_{\mathrm{cr}}$ in the antiferroelectric phase and decreases monotonically in the ferroelectric phase. The relaxation time of the order of ${10}^{\mathrm{\ensuremath{-}}5}$ s near ${\mathit{E}}_{\mathrm{cr}}$ in the antiferroelectric phase for the field-enforced transition is extremely low in contrast to that of the order of ${10}^{\mathrm{\ensuremath{-}}8}$ s near the transition temperature in the paraelectric phase for the paraelectric-ferroelectric phase transition.