The thickness dependence of ferroelectric and magnetic properties in epitaxial BiFe[O.sub.3] thin films

The ferroelectric and magnetic properties of multiferric epitaxial BiFe[O.sub.3] thin films are investigated in the framework of a general Landau free energy function. The film thickness dependence of epitaxial strains due to relaxation by misfit dislocations during film deposition is incorporated into the model by using an effective substrate lattice parameter, thereby explaining the thickness dependence of ferroelectric and magnetic properties in BiFe[O.sub.3] epitaxial thin films.