摘要
用水热法合成了立方相ＫＮｂ０．７７Ａｌ０．２３Ｏ２．７７．通过调整初始铌源和反应介质的ＫＯＨ浓度，还得到了正交相钙钛矿和一新相化合物．立方相产物采用ＸＲＤ、ＤＳＣ和ＸＰＳ进行表征．低于１０００℃的热处理不能导致立方ＫＮｂ０．７７Ａｌ０．２３Ｏ２．７７发生结构相变．阻抗谱测量结果表明，离子输运机制归属于小极化子．而正交的同组分样品结构不稳定，在高温发生结构相变，导致电导率不连续．水热法得到的立方ＫＮｂ０．７７Ａｌ０．２３Ｏ２．
Cubic KNb\-\{0.77\}Al\-\{0.23\}O\-\{2.77\} is initially synthesized by low temperature hydrothermal synthesis, whereas high temperature ceramic method can only produce the orthorhombic phase of the parent KNbO\-3 structure. By tuning the niobium species and KOH concentration, we have obtained orthorhombic KNbO\-3 and an intermediate phase. The cubic product was examined by X\|ray diffraction, differential scanning calorimeter, and X\|ray photoelectron spectroscopy. High temperature treatment up to 1 000 did not result in phase transition, reflecting a high structural stability. The transport mechanism can be ascribed to the small polarons. However for the orthorhombic counterpart, the discontinuty may be arised from the structural transformation due to the structural instability.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1999年第4期511-514,共4页
Chemical Journal of Chinese Universities
基金
国家自然科学基金
中国博士后科学基金
吉林大学无机合成与制备化学开放实验室基金
关键词
水热合成
离子电导
氧离子电解质
电解质
立方相
Low temperature hydrothermal synthesis, Structural transition, Ionic conduction
