Understanding the morphotropic phase boundary of perovskite solid solutions as a frustrated state

This paper presents a lattice model incorporating random fields and long-range interactions where a frustrated state emerges at a specific composition but is suppressed elsewhere. The model is motivated by perovskite solid solutions and explains the phase diagram in such materials including the morphotropic phase boundary (MPB) that plays a critical role in applications for its enhanced dielectric, piezoelectric, and optical properties. Further, the model also suggests the possibility of phenomena by exploiting MPBs.