Enhanced Dielectric Properties of Pb<sub>0.3</sub>Sr<sub>0.7</sub>TiO<sub>3</sub> Thin Films by Ultrasonic Processing

Abstract

Pb0.3Sr0.7TiO3 (PST) thin films have been prepared from precursor solution sonicated for different time on Pt/Ti/SiO2/Si substrates by sol-gel method. The effect of ultrasonic processing on the chemical bonding of PST precursor solution and the thermal evolution of PST dry gel are characterized with FT-IR and TG-DT technology. The structure, dielectric properties and leakage current density of PST thin films are investigated as functions of sol ultrasonic processing time. It’s found that ultrasonic processing brings about the partial sol structure rearrangement, the delay of PST formative temperature, the reduction of crystallization and dielectric constant, and the significant improvement of leakage current, dielectric loss and the figure of merit (FOM). The results suggest that the enhancement in the quality of thin films prepared with sol-gel method can be obtained by the suitable ultrasonic processing on precursor solutions. The PST thin film prepared from precursor solution sonicated for 8 h shows the highest FOM for its appropriate tunability of 57.36% and low dielectric loss of 0.0144.