On the Dielectric Anomaly of the Deuterated Dicalcium Strontium Propionate, Ca₂Sr(C₂D₅CO₂)₆

Abstract

The deuterated dicalcium strontium propionate crystal (DDSP) was synthesized in order to investigate the role of motion of propionate ions in the phase transition of the ferroelectric dicalcium strontium propionate (DSP). The temperature dependence of the dielectric constant ε_c at 1 kHz shows an anomaly at 279.5 K (T_C) indicating a negligibly small isotope effect on T_C. The temperature dependence is well described by the Curie-Weiss law ε_c−ε₀=C(T−T_C)⁻¹ with ε₀=3.7 and C=56.2 K above T_C. The ferroelectricity of DDSP was confirmed by the observation of the dielectric hysteresis loop below T_C. The negligibly small isotope effect on T_C suggests a secondary role of the motion of the propionate ions in the mechanism of the ferroelectric phase transition of DSP.