Temperature dependence of the electrical and electromechanical properties of Ba(Zr_0.2Ti_0.8)O₃ thin films prepared by chemical solution deposition

Abstract

Thin films of Ba(Zr_0.2Ti_0.8)O₃ (BZT) were prepared on Pt/Ti/SiO₂/Si and Pt/TiOx/SiO₂/Si substrates by chemical solution deposition. The alkoxide–hydroxide method was applied. The temperature dependence of the electrical and electromechanical properties of the BZT thin films was investigated. Application of a Pt/TiOx/SiO₂/Si substrate is effective in suppressing the unknown phase formation and in obtaining high permittivity of 1080 and tunability under 400 kV/cm of 84%. The XPS depth profile reveals that titanium and oxygen are richly present close to the BZT/Pt interface of the films on a Pt/TiOx/SiO₂/Si substrate. The temperature dependences of permittivity, tunability and field-induced strain are slight between −100°C and 100°C. The piezoelectric coefficient at room temperature estimated from the slope of the displacement loop is 35 pm/V.