Lead-free (1 x)Bi0.5(Na0.80K0.20)0.5TiO3–xBa(Ti0.90Sn0.10)O3 or
(1 x)BNKT–xBTS piezoelectric ceramics with x = 0–0.20 mol fraction
were successfully synthesized by a simple conventional
mixed-oxide method. The maximum density was obtained for
the ceramics sintered at 1125 C. A pure perovskite structure was
achieved for all studied composition range, suggesting the complete
solid solutions between BTS and BNKT phases. The addition
of BTS slightly affected grain size and shape of BNKT ceramic. A
large electric field-induced strain of 0.36% corresponding to d
33 of
649 pm/V were found in BNKT–0.05BTS sample. BNKT–0.10BTS
sample was found to have relatively good piezoelectric
(d33 = 215 pC/N), dielectric (er = 1721, tand = 0.0724 and
Tc = 333 C) and ferroelectric (Pr = 20.49 lC/cm2, Rsq = 0.87) properties.
Moreover, ferroelectric hysteresis behavior also indicated that
addition of BTS caused BNKT ceramic to become softer. Based on
our results, it was suggested that BNKT–BTS ceramics have potential
to be one of a promising lead-free piezoelectric candidate for
piezoelectric applications.