LAUSR

Potassium–sodium niobate (Na, K)NbO3 (NKN) powders were synthesized successfully by reducing holding time via microwave-assisted hydrothermal solvothermal method (MHSM). The obtained powders were characterized by X-ray diffraction and scanning electron microscope with special emphasis on the synthesizing temperature and holding time. The results indicate that the pure (Na, K)NbO3 powders with single perovskite structure were obtained by being calcined at 200 °C for 30 min. The powder synthesized at 200 °C for 90 min has a fine morphology and an average grain size, and its ceramics were prepared after being sintered from 1000 to 1050 °C. The microstructure, piezoelectric and dielectric properties of the obtained NKN ceramics were investigated, by comparison, the same performance were also studied for the sample prepared from conventional powders. The sample sintered at 1050 °C show optimal values of d33 = 128 pC/N, kp = 35.0%, ρ = 4.32 g/cm3, tanδ = 0.021 and εr = 509, respectively, and its Curie temperature (420 °C) is slightly higher than that (410 °C) of the conventional sample.