Pyroelectric Ba0.8Sr0.2TiO3 thin films derived from a 0.05 M solution precursor by sol-gel processing

Tetragonal Ba0.8Sr0.2TiO3 thin films with large columnar grains 100-200 nm in diameter have been prepared on Pt/Ti/SiO2/Si substrates using a 0.05 M s olution precursor by sol-gel processing. The ferroelectric phase transition in the prepared Ba0.8Sr0.2TiO3 thin films is broadened, and suppressed to 40 degrees C with a maximum dielectric constant of epsilon(r) (100 kHz) = 6 80. The observed low dissipation factor tan delta=2.6% and high pyroelectri c coefficient p = 4.586 x 10(-4) C/m(2) K at 33 degrees C render the prepar ed Ba0.8Sr0.2TiO3 thin films promising for uncooled infrared detector and t hermal imaging applications. (C) 1999 American Institute of Physics. [S0003 -6951(99)05447-9].