Enhanced Piezoelectric Response in Ferroelectric Solid Solution with Rhombohedral End Members

High-performance piezoelectric materials are, in general, ferroelectric solid solutions exhibiting morphotropic phase boundaries (MPB) – a composition driven interferroelectric instabilities. The most common approach to engineer MPB in ferroelectric systems is to choose the end members of the solid solution with different polar symmetries and anticipate for the interferroelectric transformation to occur around a certain critical composition. Here I report a non-classical approach of obtaining MPB by choosing end members of solid solutions with similar polar symmetry (rhombohedral). This is demonstrated in the alloy system x(Na0.5Bi0.5)TiO3–(1-x)Pb(Zr0.6Ti0.4)O3 (NBT-PZT) which shows a narrow MPB region (0.07 ≤ .x ≤ 0.10) at which the piezoelectric response increases remarkably by nearly 3-times to its parent end members. This strategy opens the possibility of discovering new MPB ferroelectric systems with an enhanced electromechanical response.