The specific heat of Batio₃ at low temperatures

Abstract

We have measured the specific heat of a very pure BaTiO₃ single crystal using a modified relaxation method which includes the use of a sin gle germanium chip for heater and thermometer. The measurements are made in interaction with a desk controller which allows for relaxation times below 0.5 s. The sample is a single crystal of 718mg. which was grown from suprapure product by the Czochrzlsky method. Our results follow a pure T³ dependence of the specific heat in the temperature range 3–10K showing no anomalous extra contribution. This is in contradiction with a general T^3/2 term in the specific heat of ferroelectrics in the range 2K-10K, but extrapolates smoothly with unpublished results at lower temperatures.