Preparation of (K,Na)NbO₃ Powders with Wide Grain Size Distribution

Abstract

This study is aimed at obtaining (K,Na)NbO3 powders with wide grain size distribution methods. (K,Na)NbO3 powders were successfully synthesized by different ways, including hydrothermal method, sol-gel method, and molten-salt method. The experiment results showed that the hydrothermal and sol-gel methods could not control the grain size of the (K,Na)NbO3 powders effectively . The grain size of (K,Na)NbO3 powders can be only tailored by the molten-salt method through controlling the starting oxide powder morphology, as well as crystallization temperature. The grain size was not affected by the experimental parameters whether or not the initial powders were milled. Furthermore, it has been found that the crystallization temperature could change the grain size of the powders monotonously. The (K,Na)NbO3 powders synthesized by molten salt method distributed from nanoscale to micron level, which can lay the foundation for further research on the grain size effect of (K,Na)NbO3 lead free piezoelectric ceramics.

Evaluation of structure, dielectric and electrical properties of (Li/Ta/Sb) modified (Na, K) NbO3 lead-free ceramics with excess Na concentration

“…14 To overcome these problems, different processing methods have been adopted to achieve high density ceramics, such as sol-gel 15 microwave sintering, 16 hot-pressed sintering, 17 spark plasma sintering, 18 molten salt method 19 and cold isostatic sintering, 20 etc. But these methods are too expensive and are not appropriate for largescale industrial applications.…”