Substrate effects on the novel domain structure of (100)/(001)-oriented epitaxial PbTiO3 thick films

(100)/(001)-oriented epitaxial PbTiO₃ thick films above 1 mum in thickness were grown on (001)_cSrRuO₃//(001)LaNiO₃//(001)CeO₂//(001)YSZ// (001)Si, (001)KTaO₃ and (001)SrTiO₃ substrates at 600degC by metalorganic chemical vapor deposition. The domain structures of the PbTiO₃ films grown on the various substrates having different thermal expansion coefficient were investigated by two-dimensional reciprocal space mapping using X-ray diffraction. Their similar novel domain structures consisted of a- and c-domains were observed irrespective of the kinds of the substrates. However, the tilting angles of a- and c-domains depended on their c-domain volume fractions. These results suggests that the volume fraction of c-domain is a key factor for identify the novel domain structure.