The Dependence of the Coercive Field of Tri-Glycine Sulfate on Frequency, Amplitude and Temperature

Abstract

Hysteresis loops of tri-glycine sulfate single crystal have been observed from 0°C up to Curie point. The frequency used was 0.6∼60 Hz, and the amplitude was 0∼several kV/cm. The observed coercive field was compared with the result obtained by using a two-dimentional residual nuclei model [J. Janta: J. Phys. Soc. Japan. 28 (1970) Suppl. p. 340]. The amplitude dependence of the coercive field agrees to that result, but the frequency dependence does not. This model would be too simple for the nucleation mechanism, but it is practical that the sideways domain wall motion velocity is given by the relation v=v_∞exp(−α⁄E). The temperature dependence of the activation field α is different from that of BaTiO₃. The product of α and absolute temperature is proportional to the square of the spontaneous polarization.