A suite of Nb-based piezoelectric ceramics of 0.99[Bi0.5(Na0.4K0.1)(Ti1−xNbx)]O3–0.01(Ba0.7Sr0.3)TiO3(BNKTN-BST), with x ranging from 0
to 0.030, was prepared by a conventional solid-state reaction method. X-ray diffraction patterns confirmed a single perovskite phase and the
tetragonality was found to decrease with increasing Nb ratio. The BNKTN-BST ceramic had a high field-induced normalized strain coefficient
of 634 pm/V at 2 mol% Nb content with a relatively small hysteresis compared with existing lead-free Bi-perovskite ceramics. An electric-fielddependent
X-ray study was conducted to identify the main source of the high strain and ascertain the effect of electric fields on the crystal structure.
The temperature-dependent P
−
E hysteresis loops of the BNKTN-BST ceramics were measured under an electric field of 60 kV/cm at various
temperatures, and the effect of temperature on the ferroelectricity is discussed.
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