Phase diagrams and physical properties of (111) oriented Pb(Zr1−xTix)O3Pb(Zr1−xTix)O3 thin films

• Properties of (111) oriented Pb(Zr1−xTix)O3Pb(Zr1−xTix)O3 films are studied for the first time.
• The compressive misfit strain induces the monoclinic MA phase
• The tensile misfit strain makes the triclinic γ phase and orthorhombic O phase stable.
• The tensile misfit strain induces larger physical properties than compressive strain.

Based on the phenomenological Landau–Devonshire theory, the phase diagrams and physical properties of (111) oriented Pb(Zr1−xTix)O3Pb(Zr1−xTix)O3 thin films are investigated. The “misfit strain-temperature” phase diagrams of (111) oriented thin films are more complex than that of (001) oriented thin films due to the appearance of nonlinear coupling terms in the thermodynamic potential. The monoclinic MA phase, the triclinic γ phase, the orthorhombic O phase, and the cubic C phase are stable. The compressive misfit strain induces the monoclinic MA phase, meanwhile the tensile misfit strain is beneficial to make the triclinic γ phase and the orthorhombic O   phase stable. The ferroelectric and dielectric properties are calculated which are in great agreement with the experimental measurements. Moreover, the Pb(Zr0.5Ti0.5)O3Pb(Zr0.5Ti0.5)O3 thin films with the Ti composition around the morphotropic phase boundary (MPB) have the large longitudinal dielectric and piezoelectric properties which are in accordance with the other theoretical results. Most importantly, the tensile misfit strain is prone to induce the larger dielectric and piezoelectric properties than that of compressive misfit strain, which may provide the guidance for experimental research.