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The polarization reversal of Rb2ZnCl4 crystals in the incommensurate phase near a ferroelectric phase transition (PT) under the action of harmonic electric field has been studied using harmonic analysis. During polarization reversal of a test sample under the action of harmonic electric field, a PT induced by the electric field from the incommensurate phase to the ferroelectric phase and a PT from the field-induced ferroelectric phase back to the incommensurate phase occur. The study of the active and reactive contributions to the amplitudes of current density harmonics made it possible to determine the current values of harmonic electric field intensity at which the corresponding PTs occur. [ABSTRACT FROM AUTHOR]

It is established that during the domain structure relaxation process after its removal from the equilibrium state by an alternating electric field, the sign of the coefficient c of the electric energy density decomposition in powers of a single polarization component changes from "+" to "–". The signs of the coefficient c, obtained experimentally and assumed from the Landau-Ginzburg-Devonshire theory, coincide at the initial moment after "electric field annealing". [ABSTRACT FROM AUTHOR]

The process of Rb2ZnCl4 crystal repolarization under the harmonic electric field influence in the ferroelectric phase near the Curie temperature was studied by the harmonic analysis method. The study of current density harmonics arising in the sample under the harmonic field influence allowed plotting the electric energy density Wc dependence on the polarization Pc measured in the dynamics. The Wc(Pc) time evolution was obtained after shifting of the domain structure from the equilibrium position by an alternating electric field. It was found that during relaxation the shape of Wc(Pc) changed significantly. [ABSTRACT FROM AUTHOR]

The repolarization process of Rb2ZnCl4 crystals under the influence of a harmonic electric field in the ferroelectric phase in the vicinity of the domain structure freezing temperature T * ≈ 150 K was studied using the harmonic analysis method. The study of current density harmonics that occur in the sample under the influence of a harmonic field allowed to build a dependence of the electric energy W C of the sample volume unit on the polarization P C measured in dynamics. The temperature evolution of the Rb2ZnCl4 crystal dependency W c (P c) potential relief shape in the ferroelectric phase in the vicinity of the domain structure freezing temperature was investigated. [ABSTRACT FROM AUTHOR]

Coefficients of the expansion of electrical energy in the ferroelectric phase near phase transition temperature are determined from an even power series according to polarization by studying the dynamics of repolarization in A2BX4 group crystals according to the Landau–Ginzburg–Devonshire theory. Experimental results are compared to the theoretical concepts of the Landau–Ginzburg–Devonshire theory describing dependences in static. [ABSTRACT FROM AUTHOR]

The values of the energy expansion coefficients in a series of polarization even powers on the base of study of the Rb2ZnCl4 crystal repolarization dynamics according to the theory of Landau-Devonshire are determined. The comparison of experimental results in the dynamics with theoretical concepts of the Landau-Devonshire theory describing dependencies in static is obtained. [ABSTRACT FROM AUTHOR]

Values of the expansion coefficients of electrical energy Wc in a series with respect to even powers of polarization Pc are determined using the Landau-Devonshire theory by studying the repolarization dynamics of an Rb2ZnCl4 crystal. Experimental results obtained from the dynamics are compared to theoretical representations of the Landau-Devonshire theory that describe the dependences of Wc(Pc) in statics. [ABSTRACT FROM AUTHOR]

Harmonic analysis of the dielectric hysteresis loops near the phase transition temperatureTcobtained under application of harmonic electric field with intensity above the intensity of the coercive field is presented. It is shown that, the direction of polarization reverses when the field value satisfies conditionEc=Emsin ϕ0. The increase inEcwhile approachingTcis shown to be the reason for the anomalous temperature independent behavior ofEcoer. [ABSTRACT FROM AUTHOR]