This study was conducted on the structural and electrical properties of (Ba_0.7Sr_0.3)TiO₃ thin films prepared by the sol-gel and spin-coating methods in order to investigate their applicability to electrocaloric devices. All specimens showed a tetragonal crystal structure and lattice constants of a = 3.972 Å, c = 3.970 Å. The mean grain size of specimens sintered at 800 °C was about 30 nm, and the average thickness of 5 times coated specimens was 304~311 nm. In the specimen sintered at 750 °C, The relative dielectric constant and loss of specimens measured at 20 °C were 230 and 0.130, respectively, while dependence of the dielectric constant on unit DC voltage was -8.163 %/V. The remanent polarization and coercive fields were 95.5 μC/cm2 and 161.3 kV/cm at 21 °C, respectively. And, the highest electrocaloric property of 2.69 °C was observed when the electric field of 330 kV/cm was applied.

Keywords: (Ba,Sr)TiO₃ thin films, sol-gel method, electro-caloric effect, ferroelectric, remanent polarization, dielectric constant