Thick epitaxial Pb(Zr0.35,Ti0.65)O3 films grown on (100)CaF2 substrates with polar-axis-orientation

(100)/(001)-oriented tetragonal Pb(Zr,Ti)O-3 (PZT) films, which were thicker than 2 mu m, were epitaxially grown on SrRuO3-covered (100)Si, (100)KTaO3, (100)SrTiO3, and (100)CaF2 substrates by metal organic chemical vapor deposition. The volume fraction of the (001)orientation almost linearly increased as the thermal strain increased during the cooling process from the deposition temperature to the Curie temperature. Consequently, perfectly (001)-oriented, i.e., polar-axis-oriented, thick films were obtained on CaF2 substrates with a remanent polarization of 71 mu C/cm(2). This approach to grow polar-axis-oriented PZT thick films enabled the intrinsic piezoelectricity of PZT itself to be clarified, and has potential in novel applications. (C) 2008 The Japan Society of Applied Physics.