Synthesis and Characterization of BiFeO<sub>3</sub> on OH-Functionalized Organic SAMs by Metalorganic

Abstract

Polycrystalline BiFeO3 (BFO) thin films were grown via metal organic deposition method on OH-functionalized organic self-assembled monolayers (SAMs) on glass. The stable BiFeO3 precursor solutions were obtained by using iron nitrate and bismuth nitrate as raw materials, acetic acid and glycol as solvent and citric acid as chelating agent. Firstly, the preparation and functionalization of octadecyltrichlorosilane (OTS) self-assembled monolayers on the hydroxylated glass substrates was investigated. Water contact angle measurement and atomic force microscopy (AFM) confirmed the presence of a uniform, complete monolayer. After BiFeO3 was prepared on glass substrates, the film- forming and heat treatment processing of BiFeO3 films were studied. The BFO film was characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersion spectrograph (EDS). XRD pattern indicated that the grains of sample began to grow at 450 °C, and which was made up of BiFeO3 and some impure phase. With the increase of temperature, impure phase were disappeared and the intensity of diffraction peaks strengthened. Pure BiFeO3 phase were obtained at 500 °C ~ 600 °C. When the heat treatment temperature increased above 650 °C, the impure phase appeared. SEM showed that the BFO thin film possessed a dense microstructure on OH-functionalized SAMs.