PbTiO3 content dependence of crystal structure and electrical properties of (100)-/(001)-oriented epitaxial Pb(Mg1/3Nb2/3)O3-PbTiO3 films grown by metalorganic chemical vapor deposition -: art. no. 086112

PbTiO3 content (x) dependencies of the crystal structure, and dielectric and piezoelectric properties were investigated for epitaxial (1-x)Pb(Mg1/3Nb2/3)O-3-xPbTiO(3)[PMN-PT] films, 2-3 mu m in thickness, grown on (100)(c)SrRuO3//(100)SrTiO3 substrates. (100)-/(001)-oriented epitaxial films with the x ranging from 0 to 1 were successfully grown at 650 degrees C by metalorganic chemical vapor deposition irrespective of x. The constituent phase changed from a rhombohedral (pseudocubic) single phase, a mixture phase of rhombohedral (pseudocubic) and tetragonal phases, and a tetragonal single phase with increasing x. The film with the mixture phase was formed when x=0.40-0.55, which was different from that reported for single crystals. The dependence of relative dielectric constant on x was maximum at the mixed phase region, which was similar to the case of a PMN-PT sintered body, but the magnitude of these dependencies was relatively lower than the reported one for the single crystals and sintered bodies. The longitudinal piezoelectric coefficient (d(33,f)) and the transverse coefficient (e(31,f)) of 100-120 pm/V and similar to-11.0 C/m(2) were calculated, respectively, for the film with x=0.39, which corresponds to a larger x edge of the rhombohedral (pseudocubic) region.