摘要
以分析纯Na2CO3,K2CO3和Nb2O5为原料,以Na2CO3-K2CO3(摩尔比1:1)为熔盐,采用熔盐法在700～850℃保温4h合成了Na0.5K0.5NbO3粉体。研究了合成温度、熔盐含量对粉体形貌的影响。XRD分析结果表明:通过熔盐法可以在700℃下合成纯钙钛矿结构的Na0.5K0.5NbO3粉体;SEM分析显示:随着合成温度的升高,粉体形貌从圆球状转变为立方状,进一步提高合成温度,粉体形貌开始变得不规则;此外,合成粉体的尺寸随着熔盐含量的增加而增大,且粉体团聚现象明显减弱。以熔盐法合成的Na0.5K0.5NbO3粉体为原料,采用传统固相烧结法制备Na0.5K0.5NbO3陶瓷,经1060℃烧结后,Na0.5K0.5NbO3陶瓷具有优异的压电性能和介电性能,其中压电常数d33=124pC/N,介电常数εT/ε=345,居里温度T达402℃。
Na0.5K0.5NbO3 powders were synthesized by the molten salt method,using Na2CO3,K2CO3 and Nb2O5 as raw materials in the molten salt fluxes of Na2CO3-K2CO3 （mol ratio 1∶1） at 700-850 ℃ for 4 h.The effects of synthesized temperature and content of molten salt on the crystal morphology of Na0.5K0.5NbO3 powder were studied.The XRD results show that pure perovskite structure of Na0.5K0.5NbO3 powder could be synthesized at 700 ℃.The SEM results reveal that the crystal morphology of Na0.5K0.5NbO3 powder changes from spheroid to cube,and then become irregular,with temperature increasing.In addition,the grain size increased and the agglomeration of the NKN powders decreases clearly,with the molten salt content increasing.The Na0.5K0.5NbO3 ceramics were prepared by conventional solid phase sintering,using the powders synthesized by the molten salt method as raw materials at 1060 ℃,and the Na0.5K0.5NbO3 ceramics exhibit good dielectric and piezoelectric properties.The piezoelectric constant d33 reaches to 124 pC/N,the dielectric constant εT33/ε0 is 345,and the Curie temperature Tc is 402 ℃.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2010年第1期120-124,共5页
Journal of Synthetic Crystals
基金
国家自然科学基金(No.50962007
50562002)
江西省自然科学基金(2007GZC1258)
江西省教育厅青年科学基金(GJJ09533)
关键词
熔盐法
铌酸钾钠
合成温度
熔盐含量
molten salt method
Na0.5K0.5NbO3
synthesis temperature
centent of molten salt
作者简介
李月明（1965-），男，江西省人，博士，教授。E-mail：lym6329@163．com
