Brillouin Scattering Study of Deuterated Dicalcium Strontium Propionate, Ca₂Sr(C₂D₅CO₂)₆

抄録

Brillouin scattering spectra of deuterated dicalcium strontium propionate (DDSP) have been observed as a function of temperature near the paraelectric-ferroelectric phase transition temperature T_C (279.5 K). The elastic stiffness constants c_ij in the giga hertz range are determined by the Brillouin frequency shift in the temperature region 260–300 K. The longitudinal acoustic modes propagating along the tetragonal [100] and [001] directions show a smaller anomaly at T_c than that of the non-deuterated DSP reported previously. The elastic dispersion Phenomena are discussed with particular emphasis on the role of the motion of the propionate molecules in the phase transition mechanism of DSP and DDSP.