Fabrication and electrical properties of sol-gel-derived Ba0.8Sr0.2TiO3 ferroelectric films from a 0.05-M spin-on solution

Barium strontium titanate (Ba0.8Sr0.2TiO3) films with good ferroelectricity have been obtained by a developed sol-gel processing, using a 0.05-M spin-on solution. X-ray diffraction and Raman spectroscopy investigations showed that the Ba0.8ST0.2TiO3 film exhibited a tetragonal structure at room temperature. Field-emission scanning electron microscopy measurements revealed that large columnar grains with the size of 100 to 200nm in the film were formed from the highly dilute spin-on solution with layer-by-layer homoepitaxy. Electrical measurements for the prepared Ba0.8Sr0.2TiO3 film showed a remnant polarization of 3.5 mu C/cm(2), a coercive field of 53 kV/cm, two distinctive phase transitions, lower dissipation factor, and good insulating properties. These results indicate the sol-gel-derived Ba0.8Sr0.2TiO3 film from a 0.05-M solution is suitable for uncooled infrared detector applications.