Fabrication and characterization of pyroelectric Ba0.8Sr0.2TiO3 thin filmsby a sol-gel process

A sol-gel process was used to prepare pyroelectric Ba0.8Sr0.2TiO3 thin film s with large columnar grains (100-200 nm in diameter) on Pt/Ti/SiO2/Si subs trates, via using a 0.05M solution precursor. The relationship between diel ectric constant and temperature (epsilon (r)-T) showed two distinctive phas e transitions in the Ba0.8Sr0.2TiO3 thin films. Both the remnant polarizati on and the coercive field decreased as the temperature increased from -73 d egreesC to 40 degreesC. Its low dissipation factor (tan delta = 2.6%) and h igh pyroelectric coefficient (p = 4.6 x 10(-4) C . (m(2).K)(-1) at 33 degre esC), together with its good insulating properties, made the prepared Ba0.8 Sr0.2TiO3 thin films promising for use in uncooled infrared detectors and t hermal imaging applications.