Effect of Sr and Ba-doping in optical and electrical properties of KNN based transparent ceramics

摘要

Sr2+/Ba2+ modified potassium sodium niobate transparent ceramics [(K0.5Na0.5)1−2x(Sr0.75Ba0.25)x]0.93Li0.07Nb0.93Bi0.07O3 (KNNLB:Sr2+/Ba2+) were fabricated via hot-pressing, using Li and Bi as sintering aids. The crystal structure, microstructure, optical, piezoelectric and dielectric properties of KNNLB with varied Sr2+/Ba2+ content were investigated. The optical transparency of such ceramics is up to 60 % in the UV–visible region and close to 100 % in the infrared region. Moreover, the optimum dielectric and piezoelectric performances of εr = 1679, d33 = 151 pC/N and tanδ = 0.026 were obtained for KNNLB:Sr2+/Ba2+ ceramics with x = 0.025. Consequently, the doping of Sr2+/Ba2+ is considered as an effective way to improve electrical properties and maintain excellent optical properties of the fine-grain transparent ceramics.