Crystal orientation dependence of the out-of-plane dielectric properties for barium stannate titanate thin films

The orientation-dependent out-of-plane dielectric properties of barium stannate titanate (Ba(Sn0.15Ti0.85)O3 (BTS)) thin films prepared by sol–gel method were investigated. Films with (1 0 0), (1 1 0), and (1 1 1) orientation were grown on LaNiO3-buffered (1 0 0), (1 1 0), and (1 1 1) LaAlO3 (LAO) single-crystal substrates, respectively. The different temperature of the dielectric constant maximum (Tm) of the BTS thin films with different orientation was believed to be attributing to stress inside the films. Films with the (1 1 1) orientation had higher relative dielectric constant and tunability than (1 0 0)- and (1 1 0)-oriented films. This difference in dielectric properties in these three kinds of oriented BTS films may be attributed to change in the direction and magnitude of electric polarization in orientation engineered BTS films and stress in the films.