Ba0.5Sr0.5TiO3 thin films on alumina substrates were prepared by Chemical Solution Deposition. Upon annealing at 900 °C the films with thicknesses from 70 nm to 600 nm crystallized in the perovskite phase. The films had uniform and dense in-plane microstructures. The dielectric permittivity increased with the film thickness in the range from 70 nm to 170 nm at 100 KHz and in a broader thickness range, to 310 nm, at 10 GHz. A further increase of the film thickness resulted in lowering of the dielectric permittivity within the measured frequency range. The observed decrease is probably related to the presence of intergranular cracks in the thicker films, presumably generated as a consequence of stresses due to the mismatch between the thermal expansion coefficients of the film and the substrate.
COBISS.SI-ID: 27420967