Effect of Low-Temperature Frit on the Sintering Behavior and Properties of 0.95K<sub>0.49</sub>Na<sub>0.51</sub>NbO<sub>3</sub>-0.05LiSbO<sub>3</sub> Lead-Free Piezoceramics

Abstract

The effects of low-temperature frit Li2O-Na2O-K2O-B2O3-SiO2-CaO-BaO-ZnO (abbreviated as BS) on the sintering behavior and electrical properties of 0.95K0.49Na0.51NbO3- 0.05LiSbO3 (abbreviated as KNN-LS) lead-free piezoceramics were investigated. The sintering temperature of the KNN-LS ceramics can be reduced from 1080 °C to 1000 °C due to the addition of BS frit. For the 0.5 wt% BS-doped KNN-LS ceramics, which are sintered at reduced temperature of 1000 °C for 2 h, remain relatively high piezoelectric constant d33 (195 pC/N) and planar electromechanical coupling coefficient kp (40.7%). In addition to other optimization effects, such as reduction of dielectric loss from 3.6% to 2.7% and increment of mechanical quality factor Qm from 48 to 70, this BS frit was experimentally proved to be good for low temperature sintering of KNN-based ceramics while maintaining high piezoelectric response.