LaNiO3 seed layer induced enhancement of piezoelectric properties in (1 0 0)-oriented (1 − x)BZT–xBCT thin films

The (1 0 0)-oriented ferroelectric lead-free (1 − x)Ba(Zr0.2Ti0.8)O3–xBa0.7Ca0.3TiO3 (BZT–xBCT) thin films were grown on Pt(1 1 1)/Ti/SiO2/Si substrates by sol–gel method, and LaNiO3 (LNO) seed layer was introduced between the film and the substrate. The insertion of LNO seed layer greatly improves the quality of the films and enhances the piezoelectric properties. Both of the compositions, x = 0.50 and x = 0.55, have relatively higher d33 values around MPB, and the piezoelectric coefficient is 113.6 pm/V and 131.5 pm/V, respectively. The result of ɛr ∼ T spectrum implies that dielectric permittivity has a weak temperature dependence from 30 °C to 150 °C.