The tunability and dielectric properties of the compositionally graded Ba(Zr _x Ti_1−x )O₃ thin films

The compositionally graded Ba(Zr _x Ti_1−x )O₃ films with a compositional gradient from BaTiO₃ to BaZr_0.35Ti_0.65O₃ were fabricated on LNO-buffered Pt/Ti/SiO₂/Si substrates by a sol-gel deposition method. In order to confirm the compositional gradient, a combination of X-ray Photoelectron Spectroscopy (XPS) and Ar ion etching was employed to produce the composition depth profile. Dielectric constant peaks, common to a ferroelectric transition, were not observed in the temperature range from −50 to 100 °C, within which the dielectric constant showed negligible temperature dependence. The compositionally graded Ba(Zr _x Ti_1−x )O₃ thin films with weak temperature dependence of tunability could be attractive materials for situations in which precise control of temperature would be either impossible or too expensive.