Effect of stress distribution on domain structure in epitaxial PbTiO3 thin films deposited by sputtering

Epitaxial PbTiO3 thin films with different thickness were deposited on the MgO (001) substrates by the reactive D.C. magnetron sputtering. The stress distribution with the film thickness was calculated by finite element method. With increasing film thickness, stress changes from tensile stress to compressive stress. It may cause the domain structure variation. The volume fraction of the c-domains, (alpha, was examined utilizing X-ray diffraction technique, alpha increased rapidly with an increase in the film thickness up to 100 nm. But above 100 nm, alpha was saturated with similar to 90%. In the annealed films, above 100 nm, alpha decreased to similar to 75% from similar to 90%. Below 100 nm, however, alpha was not scarcely changed. This could be explained by the calculated result of the stress distribution with increase in the film thickness.