Crystallographic and Ferroelectric Properties Subjected to Two-Dimensional Stress in c-Axis-Oriented PbTiO3 Thin Films

Relationships among Curie point, spontaneous polarization, lattice parameters with consideration of spontaneous strain and piezoelectric charge coefficient were calculated as functions of two-dimensional stress in c-axis-oriented PbTiO3 thin films using a modified Devonshire form of the elastic Gibbs free energy. A compressive stress of approximately 500 MPa was predicted by a finite-element method analysis of the PbTiO3/Pt/Ti/SiO2/Si structure. A 90° C shift in the Curie point was estimated from the compressive stress, and shifts of other properties were accompanied with a shift of phase transition.