Effect of heat treatment on the structure and properties of chemical solution processed multiferroic BiFeO3 thin films

In this work, we report on the growth and characterization of polycrystalline BiFeO3 (BFO) thin films deposited on indium tin oxide (ITO) coated glass substrates via the chemical solution deposition technique. The as-deposited films were crystallized by heat treatment at various temperatures for 1 h in various atmospheres, i.e. oxygen, air and nitrogen. Grazing angle X-ray diffraction (GIXRD) analysis of the heat treated films revealed that both annealing temperatures as well as the atmosphere, had a pronounced effect on the formation of pure perovskite-type BiFeO3 phase. Ferroelectric measurements showed that the films heat treated in nitrogen showed superior characteristics to those heat treated in air and oxygen with a remanent polarization of 0.52 mu C/cm(2) and 1.9 mu C/cm(2) for the films annealed at 600 degrees C and 650 degrees C respectively at an applied field of 60 kV/cm. BiFeO3 films annealed in nitrogen also showed maximum dielectric constant (epsilon(r) similar to 300), superior leakage resistance and magnetic properties over other films.