Phase Purity Control of Nanostructured Bismuth Ferrite Thin Film Synthesized via Sol–Gel Method with Heat Treatment Parameters

In this work, the preparation of high purity BiFeO3 (BFO) thin films by a specific wet chemical route was investigated. Single-phase BFO thin films were grown on glass substrates via a simple sol-gel spin coating technique at relatively low temperature using bismuth nitrate and iron nitrate as precursors. The effect of heat treatment parameters including temperature, time, and rate of calcination on formation of impurity phases was studied. The as-prepared thin films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD patterns indicated that the BFO thin films were mainly composed of a rhombohedral BFO phase with a minor impurity phase by increasing temperature and time of annealing as well as decreasing the rate of calcination. SEM images revealed that the matrix was uniform and no segregation of impurity phase was detected.