Thickness dependence of the properties of epitaxial barium strontium titanate thin films

Heteroepitaxial BaxSr1 − xTiO3 thin films of different thicknesses have been studied in the paraelectric phase at a temperature of 600°C. The lattice parameters of the film have nonlinear dependence on the thickness. The misfit strain and unit cell volume increase with decreasing thickness. The behavior of the misfit strain with variations in the thickness is well described in the model of the double electric layer formed during the synthesis of the film at the interface with the substrate.