Dielectric properties of betaine arsenate crystal near the phase transition Original Research Article

Dielectric measurements for single crystal of betaine arsenate (CH3)3NCH2COO·H3AsO4(CH3)3NCH2COO·H3AsO4 connected with the ferroelectric phase transition at 119 K were performed. The temperature dependence of electric permittivity was measured at dc electric fields up to 700 kV/m. The results show significant suppression of the dielectric constant by the application of dc field. Deviation from the classical behavior was observed. The electric permittivity was also measured in the paraelectric phase at constant temperature as a function of electric field intensity up to 700 kV/m. The electric permittivity might be well described by the classical relation with additional term including contribution to permittivity coming from clusters. The fit parameters indicate that the polar-clusters carries polarization P0=0.7P0=0.7–View the MathML source4.910-3cm2 with the clusters size of L=12L=12–20 nm.