Comparison of electrical properties of (100) / (001)-oriented epitaxial Pb(Zr_0.35, Ti_0.65)O₃ thin films with the same (001) domain fraction grown on (100)Si and (100)SrTiO₃ substrates

Epitaxial tetragonal Pb (Zr0.35 Ti0.65) O3 (PZT) films with a (100) (001) orientation and one and three in-plane variants were grown, respectively, on (100)c SrRu O3 (100) SrTi O3 and (100)c SrRu O3 (111) Pt (100) yttria stabilized zirconia (YSZ) (100) Si substrates by pulsed-metalorganic chemical vapor deposition, and their domain structure and electrical properties were investigated systematically. PZT films with the same volume fraction of c domains were grown on SrTi O3 and Si substrates by controlling the deposition temperature and film thickness. The relative dielectric constants at 1 kHz were 370 and 450, respectively, for the films on the SrTi O3 and on the Si, even though both films had the same volume fractions, whereas the dielectric losses were almost the same. The remanent polarization and coercive field at the maximum applied electric field of 350 kVcm were almost the same for both films, 30 μC cm2 and 135 kVcm, respectively. These results suggest that the key factor determining the ferroelectric property in epitaxial ferroelectric film is the relative volume fraction of c domains.