Dependence of thermal stability and thermomechanical characteristics of non-crystalline chalcogenides in the Cu-As-Se system on copper content

We have developed a modified power-compensation DSC to evaluate the electrocaloric properties of ferroelectrics. With this apparatus, latent heat of electric-field-induced phase transition in Ba_0.73Sr_0.27TiO₃ (BST) ferroelectric ceramics has been investigated in detail. It varies with temperature and reaches its climax at 25°C, close to the ferroelectric-paraelectric phase transition temperature, when induced by the same electric field of 15 kV cm^-1. The theoretical saturated endothermicity induced by enough high electric field at 25°C is expected to 0.59 J g^-1, which is 84% of the total phase transition latent heat of BST. At last the origins of difference between exothermicity and endothermicity are discussed.