【摘要】 选取室温下为正交-四方两相共存的0.94(Na0.52K0.48)Nb03-0.06LiNb03为基方,过量添加1.5mol%的Na2CO3和1mol%的CuO,采用传统固相法制备样品,研究其显微形貌、异常长大晶粒和小品粒的相结构以及晶粒和液相成分。结果表明,CuO的添加有助于液相在较低烧结温度下形成,从而促进晶粒生长,也有助于样品的致密化烧结:样品中的异常长大晶粒和部分小品粒都具有品格常数相似的钙钛矿相结构;Cu可以固溶入KNLN主晶相中,但其固溶度有限,晶粒边缘成分的钠含量高于钾含量,而液相成分中的钾含量高于钠含量,在KNLN-CuO的液相烧结过程中存在明显的分凝情况。更多还原

【Abstract】 0.94(Na0.52K0.48)NbO3-0.06LiNbO3 with excessive addition of 1.5 mol% Na2CO3 and 1 mol% CuO was synthesized via the traditional solid state reaction. The microstructure, the crystal structure of the abnormal growth grains and the small grains, and the composition of the grains and the liquid phase were thoroughly investigated. The result indicates that the addition of CuO induce the formation of the liquid phase at the relative low sintering temperature, which could promote the grain growth and the densification of the ceramics. The abnormal growth grains and the small grains possess the perovskite structure with the pretty similar lattice constant. Cu ion could dissolve into the lattice of KNLN. However, the degree of the solubility is limited. The content of Na in the grain boundary is higher than that of K. Meanwhile, it is the opposite case for the liquid phase. The segregation could be evidently observed in the sintering process of KNLN-CuO.更多还原