[17] Epitaxial BiAlO₃ thin film as a lead-free ferroelectric material

We fabricated high quality epitaxial BiAlO₃ thin films that exhibited a relatively high c/a ratio of about 1.05 with a pseudotetragonal structure. On the atomic force microscope morphology of the BiAlO₃ thin film, we observed large terraces with a width of about 1000 Å and terrace heights of nearly the same to one lattice constant. This indicates that the BiAlO₃ thin film has an ideal layer-by-layer growth mode. The BiAlO₃ thin film also showed a good ferroelectric property with a high remanent polarization of about 29𝜇C/cm².