Electric-field-induced phase-change behavior in (Bi0.5Na0.5)TiO3-BaTiO3-(K0.5Na0.5)NbO3: A combinatorial investigation

Abstract

The electric-field-induced strain behavior in (1 - x - y)(Bi0.5Na0.5)TiO3-xBaTiO(3)-y(K0.5Na0.5)NbO3 electroceramics has been studied using a combinatorial technique. A stoichiometrically graded sample was produced to contain compositions across the ternary phase diagram between the two end-member components of 0.93(Bi0.5Na0.5)TiO3-0.07BaTiO(3) and 0.86(Bi0.5Na0.5)TiO3-0-14(K0.5Na0.5)NbO3. Both composition and structural information were measured simultaneously during the application of electric fields using secondary Xray fluorescence and high-energy X-ray microdiffraction, respectively. An initial electric-field-induced distortion from the pseudo-cubic structure is seen across all compositions, while those with a greater concentration of BaTiO3 also undergo an electric-field-induced phase transformation. The microstructural contribution to the macroscopic strain within the 0.93(Bi0.5Na0.5)TiO3-0.07BaTiO(3) end member is quantified at a field strength of 5.5 kV mm(-1); 0.08% and 0.11% of the measured macroscopic strain of 0.4% is contributed by the induced ferroelastic domain texture and the volumetric strain associated with the electric-field-induced phase transformation, respectively.