Detection of morphotropic phase boundary of (Bi1/2Na1/2)TiO3-Ba(Al1/2Sb1/2)O3 solid-solution ceramics

A solid-solution system, (1-x)(Bi1/2Na1/2)TiO3-xBa(Al1/2Sb1/2)O-3 (BNT-BAS100x), was fabricated by a conventional ceramic fabrication process. The morphotropic phase boundary (MPB) between rhombohedral and pseudocubic phases of BNT-BAS100x was clarified to be at approximately x=0.045, and the highest normalized strain d(33)* of 532 pm/V was obtained at this composition. This study also revealed that the MPB composition of a BNT-based solid solution shifts to a BNT-rich composition as the tolerance factor t of the end member increases, and t of the MPB composition is always approximately 0.983. This indicates that the MPB position can be predicted from t values of the end members.