PbTiO3SrTiO3, and PbTiO3-Al2O3 composite and multilayer films prepared by sol-gel technique

PbTiO3 and SrTiO3 single phase films and PbTiO3-Al2O3 composite and multilayer films were prepared by the sol-gel method using dip- and spincoating deposition techniques. The films were characterized by optical microscopy, X-ray diffractometry, Alpha Step profilometer, Rutherford back-scattering and Fourier transform far infrared spectroscopy. It was found that the presence of Al2O3 in composite films blocks the PbTiO3 crystallization even at the temperature 800 degrees C whereas in multilayer films the crystallization is retarded to a certain extent only. FT FIR spectroscopy has revealed in PbTiO3 films the well-pronounced soft mode at frequency 82cm(-1) slightly lower than in bulk crystals which indicates some compressive internal stresses. In SrTiO3 films the effective soft mode damping increases with decreasing film thickness, which demonstrates the role of stresses induced by the substrate.