Influence of SrZrO3 addition on structural and electrical properties of (K0.45Na0.51Li0.04)(Nb0.90Ta0.04Sb0.06)O3 lead-free piezoelectric ceramics

• (1−x)(K0.45Na0.51Li0.04)(Nb0.90Ta0.04Sb0.06)O3−xSrZrO3 was investigated.
• The structure of coexisting phases was found to transform with SrZrO3 content.
• The relaxor behavior of the ceramics was enhanced by increasing SrZrO3 content.
• The variation of εr of the poled and de-poled ceramics is related to the structure.

(1−x)(K0.45Na0.51Li0.04)(Nb0.90Ta0.04Sb0.06)O3−xSrZrO3 lead-free piezoelectric ceramics were prepared by a conventional ceramic fabrication technique, and the influences of SrZrO3 (SZ) on the crystal structure and dielectric properties were investigated. The crystal growth and the densification of the ceramics were promoted by increasing SZ content. A secondary phase K3Li2Nb5O15 was formed when SZ content >1 mol%. The coexistence of orthorhombic–tetragonal phases was found to transform from the phase boundary near tetragonal side to orthorhombic side as SZ content increased from 1 mol% to 4 mol%, and a pseudocubic phase was formed when 5 mol% SZ was added. The relative permittivity increased, and the dielectric diffuse phase transition behavior of the ceramics was slightly enhanced with increasing SZ. The piezoelectric properties of the ceramics trend to deteriorate as SrZrO3 content increased.