Microstructure and properties of Bi2 O3 doped 0.8(K0.52 Na0.48) NbO3-0.2KSr2 Nb5 O15 lead-free ceramicsInspec keywordsOther keywords

The 0.8(K-0.52 Na-0.48)NbO3 -0.2KSr(2) Nb-5 O-15 -yBi(2) O-3 (0.8KNN-0.2KSN-yBi(2) O-3) lead-free ferroelectric composite ceramics were synthesised using rod-like KSr2 Nb-5 O-15 (KSN) and isometric (K-0.52 Na-0.48)NbO3 (KNN) particles as raw material. Effects of Bi-2 O-3 doping content on microstructure, electrical, and optical properties were researched. The results indicated that the addition of Bi-2 O-3 helps to densify 0.8KNN-0.2KSN-y Bi-2 O-3 ceramics within limits without changing phase structure and microstructure. The dielectric constant and phase transition dispersion degree increased with the increase of Bi-2 O-3 while the dielectric loss decreased. Besides, the dielectric tunability was maintained in the range of 43.7 similar to 51.8%, and reached its maximum when Bi-2 O-3 content was 1 wt%. In addition, the remnant polarisation P r and coercive field E c decreased with the increase of Bi-2 O-3, as well as the optical transmittance of 0.8KNN-0.2KSN, but the transmittance of all samples was above 48%.