Elevating electrical properties of (K, Na)NbO <sub>3</sub> ceramics via cold sintering process and post‐annealing
Baoyu Deng, Yiming Ma, Tianxiang Chen, Huajing Wang, Jinfeng Lin, Cong Lin, Xiao Wu, Chunlin Zhao, Tengfei Lin, Min Gao, Xinghua Zheng, Changqing Fang
Abstract
Abstract Dense (K, Na)NbO 3 ceramics are successfully fabricated via the cold sintering process at 350°C under a uniaxial pressure of 400 MPa for 4 h. Equimolar KOH and NaOH solutions were utilized as a transient alkaline flux. The microstructure and dielectric properties were studied in detail. Scanning electron microscope and the relative densities reveal dense structures of the ceramics. After post‐annealing at 800°C for 1 h, the ceramics show good electrical performance. The relative dielectric permittivity is 829 (at 10 kHz) at room temperature, and the piezoelectric constant ( d 33 ) reaches up to 148 pC/N. The cold sintering technique with equimolar KOH and NaOH solutions as a transient alkaline flux endow KNN ceramics with excellent dielectric and piezoelectric properties, showing a potential way to fabricating other KNN‐based ceramics at low temperature.