Preparation and Performances of KNN-based Lead-free Transparent Ceramics

Using conventional solid-phase sintering technique combined with a special atmosphere controlling technique,KNN-based lead-free transparent ceramics,x Ba(Sc0.5 Nb0.5)O3-(1-x)(K0.5N0.5)NbO3(xBSN-(1-x) KNN in simplified form),are prepared and investigated.The XRD,micro-structure,dielectric performance and optical transparency are investigated.The results show that such ceramics are of pseudocubic-Perovskite structure without any other impure phase.The grain size is comparable to the light wavelength and the grains are highly condensed without evident crystal borders.When x=0.05,d33 can reach up to 110 pC/N maximally.Such ceramics are of excellent transparency and the optical transparency reaches about 47 % in the visible light range,and the optical transparency is near 70 % at the near-infrared wavelength 2 500 nm.Such ceramics are a type of environment-friendly lead-free transparent ceramics which is promising in replacing lead-based transparent ceramics.