Electrical properties optimization of Ba0.9Sr0.1TiO3 thin films deposited by sol-gel

This paper reports a study of Ba0.9Sr0.1TiO3 films deposited on Pt/Ti/SiO2/Si substrates. The annealing temperatures were 750 degrees C, 850 degrees C and 950 degrees C. An increase of the average size of gains was observed, from 60 nm at 750 degrees C to 110 nm at 950 degrees C, as well as an increase of the dielectric constant, remnant polarization and tunability. When the annealing time was decreased from 1 hour to 15 min, the dielectric constant and remnant polarization values have been increased. The optimized annealing conditions (950 degrees C for 15 min) give the following results: epsilon(r) = 780 and tg delta = 0.01 at 100 kHz, Pr = 13 mu C/cm(2), Ec = 63 kV/cm and a tunability of 55%.