Single crystalline PbTiO3 films have been epitaxially grown on SrTiO3 substrates by molecular beam epitaxy (MBE) using a radio-frequency atomic oxygen source. High-resolution XRD results show that high-quality PbTiO3 epilayers were grown on SrTiO3 substrates with a full width at half maximum as low as 3.2 arcmin. High-resolution TEM observations show a clear and well-defined PbTiO3/SrTiO3 interface and confirm the epitaxial growth of the PbTiO3 layer. It suggests that it is promising to use the radio-frequency atomic oxygen source to grow high-quality ferroelectric oxide films. (C) 2009 Elsevier B.V. All rights reserved.