Electric-field-induced volume change and room temperature phase stability of (Bi1/2Na1/2)TiO3-x mol. % BaTiO3 piezoceramics

Phase stability of (1 - x) (Bi1/2Na1/2)TiO3-x BaTiO3 (0 <= x <= 0.15) under electric field was investigated by measuring volume changes during a bipolar poling cycle. The unique nature of field-dependent phase stability with three distinctive regions is revealed by comparative studies using commercial soft PZT and relaxor PLZT. For x <= 0.06 and x >= 0.13, similarly with PZT and PLZT, the axial strain expands with the contracting radial strain, but the former results in a remanent volume demonstrating an electric-field-induced phase transition. For 0.08 <= x <= 0.12, this field-induced phase transition is distinguished by negligible radial contractions implying polarization rotation. A "poling-induced" morphotropic phase boundary forms at x = 0.07. (C) 2011 American Institute of Physics. [doi:10.1063/1.3615675]