Structure and ferroelectricity of Ba_0.8Sr_0.2TiO₃ thin films prepared by a modified sol-gel processing

Quality Ba_0.8Sr_0.2TiO₃(BST) thin films with a remnant polarization of about 3.5 μC/cm², and a coercive field of about 53 kV/cm have been successfully prepared by a sol-gel processing using a 0.05 mol/L precursor solution. X-ray diffraction and field emission scanning electron microscope investigations show that the BST films exhibit a tetragonal structure (c/a = 1.009) and consist dominantly of large columnar grains of about 150 nm in diameter. The observed good ferroelectricity and insulating property render the sol-gel derived BST thin films promising for uncooled infrared detector and thermal imaging applications.