Dielectric Critical Slowing-Down in Ferroelectric Ca₂Sr(C₂H₅CO₂)₆

Abstract

Measurements of dielectric constant ε' and dielectric loss ε'' of Ca 2 Sr(C 2 H 5 CO 2 ) 6 along the ferroelectric axis have been made between 100 kHz and 3.3 kMHz as functions of temperature. Dielectric dispersion arising from the dipolar reorientation takes place mainly in the frequency range from about 10 7 Hz to 10 8 Hz, where ε'( T ) shows double peaks with minimums at the Curie point. ε''( T ) becomes maximum at the Curie point, and the maximum value decreases with the increase of the frequency. The results obtained can be explained by the critical slowing-down of the polarization relaxation process.