Simultaneous Measurement of Specific Heat Capacity, Thermal Conductivity and Thermal Diffusivity of Ferroelectric Ba(Ti1-x,Snx)O3 Ceramics by Thermal Radiation Calorimetry

Abstract

Simultaneous measurements of specific heat capacity, thermal conductivity and thermal diffusivity have been performed for ferroelectric Ba(Ti1-x,Snx)O3 ceramics. An apparatus based on thermal radiation calorimetry was used in the present measurement. The measurement is performed in a vacuum chamber kept at room temperature in which a disk-shaped sample is heated and cooled slowly on one face by thermal radiation from a flat heater. The values of three thermophysical properties were obtained from the temperatures and the ramp rates of both sample surfaces, the surface emissivity of the sample and the temperature of the heater surface. In this calorimetry, these thermophysical properties were independently obtained, a self-check of the reliability of the results was performed. The measurements were performed in the temperature range from 310 to 440 K. Anomalies in the thermophysical properties were observed near the ferroelectric phase transition temperature. The Curie temperatures of Ba(Ti1-x,Snx)O3 ceramics determined from the experimental results are almost consistent with those obtained by previous authors.