Orientation-dependent dielectric properties of Ba(Sn0.15Ti0.85)O3 thin films prepared by sol–gel method

The orientation-dependent dielectric properties of barium stannate titanate (Ba(Sn0.15Ti0.85)O3, BTS) thin films grown on (1 0 0) LaAlO3 single-crystal substrates through sol–gel process were investigated. The nonlinear dielectric properties of the BTS films were measured using an inter-digital capacitor (IDC). The results show that the in-plane dielectric properties of BTS films exhibited a strong sensitivity to orientation. The upward shift of Curie temperature (Tc) of the highly (1 0 0)-oriented BTS thin films is believed to be attributing to a tensile stress along the in-plane direction inside the film. A high tunability of 47.03% was obtained for the highly (1 0 0)-oriented BTS films, which is about three times larger than that of the BTS films with random orientation, measured at a frequency of 1 MHz and an applied electric field of 80 kV/cm. This work clearly reveals the highly promising potential of BTS films for application in tunable microwave devices.