Composition-dependent crystal structure, dielectric properties and temperature stability of the (1-x)CaZrO3-xSrTiO3 paraelectric thin films

The (1-x)CaZrO3-xSrTiO3 solid-solution thin films were prepared with different compositions from x = 0.05 to x = 0.45. The as-prepared thin films experienced such a crystal structure transition process from orthorhombic to pseudo cubic and then to cubic as the x increases. Among the as-prepared films, the smallest expansion ratio of lattice volume with temperatures, and the highest temperature stability of dielectric response and leakage current density at high voltage were found in the x = 0.3 thin films. The relationship between the tolerance factor and the temperature stability was analyzed from the crystal structure dependence of the absorbed thermal energy distribution. Finally, the x = 0.3 thin films were developed into thin-film capacitors, which showed high DC resistance and uniform capacitance properties. The result also shows that high temperature stability of the perovskite-type paraelectric thin films could be realized through the phase boundary design, and further improved by optimizing the temperature stability of the lattice structure.