Effect of substrate material on the crystallinity and epitaxy of Pb(Zr,Ti)O-3 thin films

Pb(Zr,Ti)O-3 thin films (Pb:Zr:Ti = 1:0.52:0.48) were prepared on various s ingle-crystal substrates via dipping-pyrolysis process by use of metal naph thenates as starting materials. The alignments of these films were examined by X-ray diffraction (XRD) theta-2 theta scans and beta scans (pole figure s). The films grown on Nb-doped SrTiO3, MgO or LaAlO3 showed an epitaxial r elationship with substrates after heat treatment at 750 degrees C, while th ose 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 SE M 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.