Strain-relaxed structure in (001)/(100)-oriented epitaxial PbTiO_3 films grown on (100) SrTiO_3 substrates by metal organic chemical vapor deposition

摘要

The authors grew (001)- and (001)/(100)-oriented epitaxial PbTiO_3 films with various thicknesses on (100)SrTiO_3 substrates. They used x-ray diffraction to measure the angles between surface normal [001] of (001)-oriented domains and [100] of (100)-oriented domains. The angles were found to be approximately 3.6° when the film thickness exceeded 1100 nm. This value is consistent with the value obtained by a geometric calculation for strain-free PbTiO_3. This result suggests that thick epitaxial PbTiO_3 films grown on (100)SrTiO_3 substrates have a fully strain-relaxed structure.