Epitaxial Pb(Zr, Ti)O3 thin films with coexisting tetragonal and rhombohedral phases

Epitaxial Pb(Zr, Ti)O₃ thin films having coexisting tetragonal and rhombohedral phases have been successfully fabricated with the film compositions that correspond to the Zr-rich region of the morphotropic phase boundary (MPB). The key to the present success is to quantitatively understand the shift of the MPB under a film stress. The present fabrication has been theoretically justified by superimposing the computed temperature-dependent film stress on the theoretical temperature-stress (T-S) phase diagram and by delineating a probable phase-transition path upon cooling the film from the processing temperature.