Thermo-electrical energy conversions in Bi0.5Na0.5TiO3-BaTiO3 thin films prepared by sol-gel method

Solid solution (1-x)Bi0.5Na0.5TiO3-xBaTiO(3) (BNT-xBT) thin films with x=0, 0.1, 0.9 and 1.0 are synthesized by sol-gelmethod. The as-prepared BNT-xBT films are crystallized into a single perovskite phase. The temperature-dependent polarizations of the thin films are measured to characterize their performances in thermo-electrical energy conversions. In BNT-0.1BT it is found that the electro-caloric refrigeration temperature change is 3.3 degrees C with the application of an electric field of 862 kV/cm at 46 degrees C. The density of electrical energy generating from a 10 degrees C temperature variation cycle is 0.68 J/cm(3). The results demonstrate that BNT-0.1BT lead-free ferroelectrics are excellent environmental-friendly energy materials for electro-caloric refrigeration and pyroelectric energy harvesting applications near room temperature. (C) 2012 Elsevier B.V. All rights reserved.