Formation and characterization of typical films Ba_0.2Sr_0.8TiO₃ using XRD, FESEM and Spectroscopy impedance

Barium Strontium Titanate (BST) thin film is a ferroelectric material that is widely researched as a material for microelectronic devices. It has a high dielectric constant, high load storage capacity, good temperature stability and even as a capacitor material. The purpose of research is to know the structure of crystal, thickness, morphology, capacitance value, dielectric constant value and dielectric loss value. These informations are very important to find a thin film BST as a good capacitor. BST thin film with Ba_0.2Sr_0.8TiO₃ structure has been made using the sol-gel method and annealed at temperature of 600°C and 650°C. The thin film of BST was characterized using XRD, FESEM, and impedance spectroscopy. The result of XRD shows that the crystalline has improved as the annealing temperature and increased with cubic structures. The FESEM in 600°C and 650°C has resulted in grain sizes of 31.3 nm; 39.1 nm and thickness of 51.36 nm, 53.59 nm, respectively. The results of impedance spectroscopy in temperatures of 600°C and 650°C with frequency of 100 Hz found that the capacitance values are 3.11846x10⁻¹¹F; 5.12881x10⁻¹¹F, the dielectric constant values are 3.52262; 4.10499 and the loss dielectric values are 0.024507 and 0.00403, respectively. The results of impedance also show the greater frequency, the smaller complex capacitance, and also the greater dielectric constant, the smaller loss dielectric. (paper)