Unique high temperature polarization stability state in Bi_(0.5)Na_(0.5)TiO_3-BaTiO_3 system at the morphotropic phase boundary

摘要

The high-temperature stability of piezoelectric property is an important merit for applications at elevated temperatures. However, understanding the depolarization mechanism is a fundamental issue that remained unclear for decades. In this study, the ex situ depolarization behavior between open-circuited and short-circuited annealed samples is measured for (1-x)Bi_(0.5)Na_(0.5)TiO_3-xBaTiO_3 (BNT-xBT) ceramics. A unique high temperature polarization stability state with respect to the prominent improvement depolarization temperature is observed for the morphotropic phase boundary (MPB) composition (x = 0.06) with open-circuited annealed samples. It is suggested that this enhancement can be attributed to the alignment of the nanodomains induced by the bias fields.