Finite-Temperature Properties ofPb(Zr1−xTix)O3Alloys from First Principles

A first-principles-derived approach is developed to study finite-temperature properties of $\mathrm{Pb}\left({\mathrm{Zr}}_{1-x}\mathrm{T}{\mathrm{i}}_x\right){\mathrm{O}}_3$ (PZT) solid solutions near the morphotropic phase boundary (MPB). Structural and piezoelectric predictions are in excellent agreement with experimental data and direct first-principles results. A low-temperature monoclinic phase is confirmed to exist, and is demonstrated to act as a bridge between the well-known tetragonal and rhombohedral phases delimiting the MPB. A successful explanation for the large piezoelectricity found in PZT ceramics is also provided.