Dielectric Relaxation in the Incommensurate Phase of {N(CH₃)₄}₂ZnCl₄

Abstract

The complex dielectric constant of {N(CH₃)₄}₂ZnCl₄ crystal has been measured in the incommensurate phase in the frequency range from 30 kHz to 10 MHz. It has been found that the dielectric dispersion occurring along the ferroelectric a-axis is of the Debye-type with a single relaxation time in the incommensurate temperature range except the close vicinity of the incommensurate-commensurate phase transition point T_c. In the incommensurate phase, the relaxation time increases nearly in inverse proportion to (T−T_c) and reaches to the value of about 1.2×10⁻⁷ sec at just above T_c.