Epitaxial Growth of PbTiO3 on MgAl2O4/Si Substrates

Lead titanate (PbTiO3) thin films are successfully sputter-deposited onto (100)MgAl2O4/(100)Si substrates at 480–550°C sputtering temperatures. It is confirmed, from X-ray and electron diffraction analyses, that the PbTiO3 films grow epitaxially on MgAl2O4 films. The crystal properties of PbTiO3 films depend on those of MgAl2O4 films strongly. The PbTiO3 films are composed of c-axis and a-axis oriented domains. The ratio of the c-axis oriented domain to the a-axis oriented domain is controllable by the cooling rate of the substrate. The dielectric constant of the PbTiO3 film is estimated to be about 100, based on C-V measurements with a metal-insulator-semiconductor structure.