Understanding the origin of the high piezoelectric performance of KNN-based ceramics from the perspective of lattice distortion

Comprehensive analysis of the temperature dependence of the crystal structure of (1−x)K0.5Na0.5NbO3–xBa(Li1/4Nb3/4)O3piezoelectric ceramics

“…Moreover, Fuentes et al 49 also found that the fraction of the orthorhombic phase in the (K 0.44 Na 0.52 Li 0.04 ) 0.97 La 0.01 Nb 0.9-Ta 0.1 O 3 ceramic was 50% when the ceramic was sintered at 1180 1C. The percentage of the orthorhombic phase in the 0.99KNN-0.01BaLN ceramic at room temperature seems to be higher than those of KNN-based ceramics; 46,48,49 it is found that BaLN addition leads to the formation of orthorhombic-rich KNN ceramics at room temperature. However, upon increasing the temperature up to 165 1C, the orthorhombic phase proportion gradually decreased from 62.9% to 52.5% while that of the tetragonal phase increased from 37.1% to 47.5%.…”

“…The orthorhombic and tetragonal phase percentages at room temperature were estimated to be 62.9% and 37.1%, respectively. When comparing the percentages of orthorhombic and tetragonal phases in 0.99KNN–0.01BaLN with those of other KNN-based ceramics, the percentages of orthorhombic and tetragonal phases in the 0.97K 0.48 Na 0.52 NbO 3 –0.03(NaSbO 3 –(Bi 0.45 Sm 0.05 )Li 0.5 ZrO 3 ) ceramic were reported to be 38.69% and 61.31%, 48 respectively. Moreover, Fuentes et al 49 also found that the fraction of the orthorhombic phase in the (K 0.44 Na 0.52 Li 0.04 ) 0.97 La 0.01 Nb 0.9 Ta 0.1 O 3 ceramic was 50% when the ceramic was sintered at 1180 °C.…”

Diffuse multiphase coexistence renders temperature-insensitive lead-free energy-harvesting piezoceramics

“…Bi 3+ and Zr 4+ are conducive to the formation of an O–T phase boundary with a DMC feature, 14 and Li + serves as a sintering aid. 15 Due to the differences in ionic radius and electronegativity between Bi 3+ and K + , Na + in the A-site, and Zr 4+ and Nb 5+ in B-site, the long-range order of the ion arrangement is broken and atomic-scale heterostructures are formed in the perovskite lattice, which induces local electrostatic and stress fields, 16 leading to the emergence of hierarchical domain configurations to reduce the system energy. These DMC-related factors are anticipated to modulate the stability of d 33 and ε r over a wide temperature range, so as to obtain a temperature-insensitive FOM (Fig.…”

Grain Growth Behavior and Electrical Properties of 0.96(K0.46−xNa0.54−x)Nb0.95Sb0.05O3–0.04Bi0.5(Na0.82K0.18)0.5ZrO3 Ceramics

“…at the A-site and Sb, Zr, Hf, etc. in the B-site of KNN, excellent piezoelectric properties comparable to those of PZT-based ceramics are obtained because of the coexistence of rhombohedral and tetragonal phases [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ].…”