Thermal hysteresis measurement methods

Pr is the actual polarization in the polymer, measured by the thermally stimulated current method, or hysteresis measurements in the case of PVDF. 

The thermal expansion of Gd2(Mo04)3 has been measured by Newnham et al. 6969) and Cummings (1970) by X-ray powder and dilatometric methods respectively. However, by X-ray study of a Gd2(Mo04)3 single crystal by Kobayashi et al. (1972) is most recent and thorough. Their data on the temperature dependence of the lattice constants and lattice volume are given in fig. 30.20. The first order nature of the transition is seen as a small discontinuous change in lattice constant with a thermal hysteresis of about 3.5°C as seen in fig. 30.21. 

---