Intrinsic properties of (100)/(001)-oriented epitaxial PZT thin films grown on (100)Si and (100)SrTiO3 substrates

Epitaxial tetragonal 150 nm-thick Pb(Zr0.35Ti0.65)O-3 (PZT) films with a (100)/(001) orientation, and one and three in-plane variants were grown at 415, 540 and 540 degrees C, respectively, on (100)(c)SrRuO3/(100)SrTiO3, (100)(c)SrRuO3/(100)(c)LaNiO3/ (100)CeO2/(IOO)YSZ/(100)Si, and (100)(c)SrRuO3/(111)Pt/(100)YSZ/(100)Si substrates by pulsed-metalorganic chemical vapor deposition, and their domain structure and electrical properties were investigated systematically. The relative dielectric constants at I kHz were 370, 400, and 450, respectively, even though all films had the same volume fraction of the c-domains, whereas the dielectric losses were almost the same. The remanent polarization and coercive field at the maximum applied electric field of 350 kV/cm were almost the same for all films, 30 mu C/cm(2) and 135 kV/cm, respectively. These results suggest that the intrinsic ferroeletric property of epitaxial ferroelectric film is determined by the relative volume fraction of the c-domains.