Laser Molecular Beam Epitaxy Growth of BaTiO₃ in Seven Thousands of Unit-Cell Layers

BaTiO₃ thin films in seven thousands of unit-cell layers hav been successfully fabricated on SrTiO₃ (001) substrates by laser molecular beam epitaxy. The fine streak pattern and the undamping intensity oscillation of reflection high-energy electron diffraction indicate that the BaTiO₃ film was layer-by-layer epitaxial growth. The measurements of scanning electron microscopy and atomic force microscopy show that surfaces of the BaTiO₃ thin film are atomically smooth. The measurements of x-ray diffraction and transmission electron microscopy, as well as selected-area electron diffraction reveal that the BaTiO₃ thin film is a c-oriented epitaxial crystalline structure.