Improved dielectric and piezoelectric properties of K/Na excessed (Na,K) NbO3 lead-free ceramics by the two step sintering process

Abstract

The Na0.5K0.5NbO3 (NKN) ceramics with K/Na excess dopants were prepared by employing the two-step sintering process. The K/Na excessed NKN ceramics were researched by varying the sintering temperature, in order to optimize their piezoelectric properties by employing a conventional sintering method. Also, the effects of dwell time for the two-step sintering process on the ceramic properties were studied. The crystalline structure of the NKN ceramics with K/Na excess dopants were measured by X-ray diffraction (XRD) analysis. The microstructure was examined by field emission scanning electron microscopy (FE-SEM). In addition, piezoelectric coefficient, d(33) and relative dielectric permittivity epsilon(r), will be discussed. In this research, we expected to improve the piezoelectric and dielectric properties of NKN lead-free piezoelectric ceramics by employing excess dopants of K/Na and the two-step sintering process. (C) 2016 Elsevier B.V. All rights reserved.