Epitaxial PbTiO3 thin films on SrTiO3(100) and SrRuO3/SrTiO3(100) substrates deposited by a hydrothermal method

Lead titanate (PbTiO3) thin film is a promising material for ultrahigh-density ferroelectric data storage systems, pyroelectric sensors and ferroelectric optical devices. In this study, high-quality epitaxial PbTiO3 thin films were deposited on SrTiO3(100) and SrRuO3/SrTiO3(100) by a hydrothermal method. The crystal orientation of the deposited film was investigated with a high-resolution X-ray diffraction mapping system. The full width at half maximum (FWHM) of the rocking curve of the (002) PbTiO3 film on SrTiO3 was 0.060. The reciprocal space mappings of (103) verified that the PbTiO3 films had perfect c-axis orientation. The self-aligned polarization was confirmed with observation using a scanning nonlinear dielectric microscope. The PbTiO3 on SrRaO3/SrTiO3(100) was used for the D-E hysteresis curve measurement and the remanent polarization was 96.5 muC/cm(2). Domain patterning was applied to a 50-nm-thick PbTiO3 film using a conductive cantilever probe. The minimum radius of the nano domain dot was 12 nm, corresponding to a data density of 1 Tbit/inch(2).