摘要
以两步熔盐法(TMS)合成片状KxNa1-xNbO3(KNN)粉体,首先以K2CO3、Nb2O5为原料,KCl为熔盐合成层状结构前驱体K4Nb6O17(K4N6),再以K4N6和K2CO3为原料,在NaCl-KCl复合熔盐中合成片状KNN粉体,研究保温时间(0～180min)和升温速率(1～10℃/min)对KNN粉体形貌的影响。结果表明:在升温速率相同的情况下,保温时间越长,立方状的KNN的含量越高;保温时间相同时,提高升温速率,容易破坏其片状形貌。当以1℃/min升至1000℃后直接自然冷却,可合成片状形貌好、径向比高的纯KNN粉体,扫描电镜照片显示晶粒长30～60μm,厚1～2μm,偏光显微照片显示该晶体颗粒为生长良好的单晶,该片状晶粒可作为制备织构化KNN压电陶瓷的优良模板剂。
Plate-like KNN powders were synthesized by a two-step molten salt method (TMS). Firstly, precursor particles K4Nb6O17 (K4N6) with layered structure were synthesized in molten KCl-salt by starting materials of Nb2O5 and K2CO3 . Secondly, plate-like KxNa1-xNbO3 (KNN) was synthesized in molten KCl-NaCl mixed salt using the K4N6 particles and K2CO3 as raw materials. The effects of soaking time (0～3 h) and heating rate (1～10 ℃/min) on micro morphology of KNN particles were investigated. When the heating rate was the same, the results show that more cubic KNN particles could be obtained if prolonging the soaking time. When the soaking time was the same, increasing the heating rate is easy to break the micro morphology of plate-like KNN particles. Pure KNN powders with high radial ratio and good plate-like morphology could be synthesized at 1000 ℃ without soaking time under the heating rate of 1 ℃/min. This synthesized particle has a length of 30～60 μm, and a thickness of 1～2 μm. Polarizing microscope images show that the synthesized particles are well-developed single crystal, and they are very suitable for templates to fabricate textured KNN-based ceramics.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2013年第S1期1-5,共5页
Rare Metal Materials and Engineering
基金
国家自然科学基金(51262011
50962007)
江西省自然科学基金(20114BAB206023)
江西省主要学科学术和技术带头人培养计划(2010DD01100)
江西省教育厅科技项目(GJJ12508)
景德镇市学科带头人项目
景德镇陶瓷学院研究生创新基金项目
关键词
铌酸钾钠
压电陶瓷
织构化
片状模板
potassium-sodium niobate
piezoelectric ceramic
texturing
plate-like template
