Composition design and electrical properties of (K0.48Na0.52)NbO3-xLiSbO3}-y{(Bi0.5Na0.5)(Zr1-zSnz)O3} ceramics

In the present study, we designed a new system, (K0.48Na0.52)NbO3-xLiSbO(3)}-y{(Bi0.5Na0.5)(Zr-1-zSnz)O-3} and systemically investigated both the piezoelectric performance under weak field and the electrostrain under large electric field. Here the isovalent additive LiSbO3 (LS) was employed to pinch the three ferroelectric phases together, while the aliovalent dopant (Bi0.5Na0.5)(Zr0.8Sn0.2)O-3 (BNZS) was introduced to further lower the Curie temperature (T-c). The enhanced piezoelectric properties were achieved by pinching the phases with different symmetries together; hereinto the ceramic with LS content of 0.05 and BNZS content of 0.03 exhibited large piezoelectric coefficient (d(33)) of 249pC/N. Besides the high piezoelectric performance under weak field, the present ceramics also exhibited large electrostrain under large electric field, ascribing to the Zr4+ and Sn4+ in BNZS. The electrostrain reached 0.27% under the electric field of 4 kV/mm(with the converse piezoelectric coefficient d(33)* of 675 pm/V), even superior to the widely used hard PZT. (C) 2017 Elsevier Ltd. All rights reserved.