Effect of substrate material on the crystallinity and epitaxy of Pb(Zr,Ti)O3 thin films

Pb(Zr,Ti)O-3 thin films (Pb:Zr:Ti = 1:0.52:0.48) were prepared on various single-crystal substrates via dipping-pyrolysis process by use of metal naphthenates as starting materials. The alignments of these films were examined by X-ray diffraction (XRD) theta-2 theta scans and beta scans (pole figures). The films grown on Nb-doped SrTiO3, MgO or LaAlO3 showed an epitaxial relationship with substrates after heat treatment at 750 degrees C, while those grown on sapphire and Si wafers exhibited polycrystalline or amorphous characteristics. Epitaxial films on SrTiO3 and LaAlO3 were found to consist of a c-axis oriented tetragonal phase, to minimize the lattice misfit with the substrates. These epitaxial films exhibited very smooth surfaces by SEM and AFM observations. In addition, the fluctuation of in-plane alignment was significantly dependent on the lattice-misfit values. (C) 1999 Elsevier Science S.A. All rights reserved.