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High strain response in ternary Bi₀.₅Na₀.₅TiO₃–BaTiO₃–Bi(Mn₀.₅Ti₀.₅)O₃ solid solutions

Ullah, Aman, Alam, Mehtab, Ullah, Amir, Ahn, Chang Won, Lee, Jae-Shin, Cho, Shinuk, Kim, Ill Won
RSC advances 2016 v.6 no.68 pp. 63915-63921
X-ray diffraction, ambient temperature, ceramics, electric field, solid solutions
In this study, a ternary solid solution (0.935 − x)BNT–0.065BT–xBi(Mn₀.₅Ti₀.₅)O₃ (BNT–BT–BMnT; x = 0–0.030) was designed and fabricated by means of a conventional fabrication process. The composition and temperature dependencies of this material’s dielectric, ferroelectric and strain behavior were systematically investigated. XRD patterns of the BNT–BT–BMnT ceramics showed a single perovskite phase with pseudocubic symmetry for all investigated compositions. The substitution of BMnT into BNT–BT was found to induce a transition from the ferroelectric to the ergodic relaxor phase, resulting in significant disruption of the ferroelectric order along with a downward shift of the ferroelectric–relaxor transition temperature TF–R to below room temperature. Accordingly, at a critical composition (2 mol% of BMnT), a high field-induced nonlinear strain of 0.45% was induced, with the normalized strain of 818 pm V⁻¹. Furthermore, the field-induced strain of the critical composition was stable at temperatures up to 100 °C owing to its stable nonpolar phase, suggesting that the developed material may be very attractive due to its temperature stability in the range of 30–100 °C. The high strain response in the critical composition was attributed to the reversible transformation between the ergodic relaxor and ferroelectric phases under the applied electric field.