Multi-scale thermal stability of niobate-based lead-free piezoceramics with large piezoelectricity

摘要

Growing environmental concerns are pushing the development of lead-free piezoceramics with both outstanding piezoelectric properties and reasonable thermal stability. Herein, we realized a large piezoelectric coefficient d(33) of 430 pC N-1 in 0.96(K0.4Na0.6)(Nb0.96Sb0.04)O-3-0.04Bi(0.5)K(0.5)Zr(0.85)Sn(0.15)O(3) (KNNS-BKZS) polycrystals by constructing a rhombohedral-tetragonal (R-T) phase boundary. Investigations of the in situ thermal stability of the piezoelectric properties on multiple scales reveal that the micro-scale piezoelectric response is much more stable compared to the macro-scale response, indicating the significant role of extrinsic contributions from domain wall movements. These findings demonstrate the relationship between multiscale properties and domain structures, revealing that the high piezoelectricity is attributed to nano-domains at the R-T phase boundary.