The effect of deposition rate and temperature on the structure and ferroelectric properties of pulsed laser deposited Bi0.95Dy0.05FeO3 thin films

Abstract

In this study, the structural and ferroelectric properties of Bi0.95Dy0.05FeO3 (BDFO) thin films prepared using pulsed laser deposition (PLD) under various deposition rates (Dr) and substrate temperatures (Ts) are investigated. Regardless of Dr in the range of 1.0–3.0 Å/s, a predominant crystallographic orientation, BDFO(001), and similar microstructure are consistently identified for BDFO films at Ts = 500 °C. Stress analysis revealed the distinct stress states with Dr. Ferroelectric properties might depend on stress in this case. The compressive stress found for the film at Dr = 3.0 Å/s results in enhanced polarization, with a 2Pr of 180 μC/cm2. In contrast, tensile stress for the film at Dr = 1.0 Å/s exhibits a lower 2Pr = 106 μC/cm2. Besides, XRD results for the films at different Ts demonstrated that the optimal temperature for BDFO growth is Ts = 500 °C, which exhibits the lowest leakage current density due to the suppressed vacancies and improved crystallinity. These findings provide comprehensive insights into the structural and ferroelectric properties of BDFO films, elucidating the impact of deposition rate on their characteristics, and significantly improving ferroelectric properties of BDFO films for the applications.