Growth of Samarium-Substituted Epitaxial Bismuth Ferrite Films by Chemical Vapor Deposition

Abstract

There is great interest in BiFeO 3 and various substituted heterostructures for ferroelectric random-access memory (RAM) and energy-efficient magnetoelectric logic and memory devices. High-quality heterostructures of these material systems with smooth topography are desirable to incorporate into functional devices. For this purpose, the direct liquid injection chemical vapor deposition (DLI-CVD) technique has been employed to grow BiFeO 3 and Bi-site samarium-substituted epitaxial films on (001)-oriented SrTiO 3 and SrRuO 3 -buffered SrTiO 3 substrates. Structural and morphological characterizations of the films are carried out using X-ray diffraction, atomic force microscopy, and scanning electron microscopy techniques. The films show textured growth and exhibit smooth morphology with root mean square roughness below 2.5 nm. Ferroelectric characteristics and memory retention in thin films are demonstrated using piezoresponse force microscopy. The thickness scaling of the switching voltage has been analyzed to validate the Kay−Dunn law for Sm-substituted BiFeO 3 and compared with that of pure BiFeO 3 .

Charge transport and dielectric characteristics of Sm x Bi1−x FeO3 thin films from the perspective of grain and grain boundary properties

“…However, in contrast to the success in studying polycrystalline electroceramics [26][27][28], there are limitations of BLM to extract reliable information about electrical conductivity and dielectric permittivity due to GB in very thin films. The Sm substitution effects on the dielectric permittivity, remnant polarization, leakage current, domain structure, local switching, microscopic approaches, and other physical properties of BSFO ceramics [29][30][31], nanoparticles [13], and thin films [32] have been reported in the literature. Although these results, it lacks a systematic study using the BLM to fit experimental data and extract useful information on the physical properties of BSFO thin films.…”