Site modification in BiFeO3 thin films studied by Raman spectroscopy and piezoelectric force microscopy

Site modification in BiFeO3 films was investigated using Raman spectroscopy and piezoelectric force microscopy to explore effect of A- and B-site modifications on structural evolution and ferroelectric behavior of doped BiFeO3 films. Our Raman results revealed the subtle structural changes in the BiFeO3 films caused by the changes of the short-range force in the crystal lattice induced by ionic radii mismatch. The observation of ferroelectric domain and the control of domain switching through an electric field in these doped BiFeO3 films were realized by piezoelectric force microscopy. Piezoelectric response of these doped BiFeO3 films illustrated dependence of their properties upon the lattice symmetry and film microstructure. (C) 2008 American Institute of Physics.