Sol-gel Derived (Pb_0.65Sr_0.35)(Zr_0.5, Ti_0.5)O₃ Ferroelectric Thin Films: Structural and Electrical Properties

Abstract

The Pb(Zr0.5, Ti0.5)O3 (PZT) is one of the ferroelectric materials used in the non-volatile memories. However, PZT usually suffers from fatigue that degrades the polarization with metallic electrodes. The high stability associated with Sr-O bonding reduces oxygen vacancies which in turn lessens fatigue and hence Sr in introduced at Pb site. In the present study (Pb0.65Sr0.35)(Zr0.5, Ti0.5)O3 (PSZT) ferroelectric thin films were successfully prepared by sol-gel method. The structural and morphological properties of the thin film were studied by x-ray diffraction and atomic force microscopy, respectively. The crystallization of the film was completed at 600°C of annealing and the root mean square roughness of the 300 nm film was around 4.5 nm. When Pb in Pb(Zr0.5, Ti0.5)O3 was substituted with 35% Sr, the coercive field increased and the remnant polarization reduced as compared to pure PZT. The films were ferroelectric at room temperature with the phase transition temperature at ~375°K. The dielectric constant and the loss tangent at room temperature were 257 and 0.023, respectively at 100 kHz.