(1. 中南大学 材料科学与工程学院，长沙 410083；
2. 中南大学 有色金属材料科学与工程教育部重点实验室，长沙 410083)
摘 要: 为了研究具有α-NaFeO2结构的复杂钴氧化物原子排列规律，采用固相反应合成了Li0.5Na0.5CoO2多晶粉末，并利用X射线衍射(XRD)、扫描电子显微分析(SEM)和透射电子显微分析(TEM)等检测手段对其形貌、晶体结构等进行了表征。结果表明：一般处理状态下，Li0.5Na0.5CoO2为片状，其晶体结构与层状LiCoO2相似，但在某些处理状态下通过TEM观察到沿[0001]带轴衍射花样中出现菱面体晶系中应该消光{10 0}的晶面族。这说明Li0.5Na0.5CoO2的晶体结构已经由菱面体结构转变成六方结构。
关键字: Li0.5Na0.5CoO2；电子衍射；晶体结构；合成
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China？
2. Key Laboratory of Nonferrous Materials Science and Engineering, Ministry of Education,
Central South University, Changsha 410083, China）
Abstract:In order to research the structure of complex cobalt oxide compounds with the similar crystallographic features of α-NaFeO2, the solid state reaction was used to prepare the Li0.5Na0.5CoO2 , whose crystal structure and morphology were characterized by X-ray diffractometry (XRD), scanning electron microscopy(SEM)，transmission electron microscopy (TEM). The results show that, under normal conditions, the platelet-like Li0.5Na0.5CoO2 and layered LiCoO2(R M) have similar crystal structures. However, the extinction spots of crystal-plane {10 0} of rhombohedral R m space group in [0001] zone axis is detected in TEM patterns, which indicates that the crystal structure of Li0.5Na0.5CoO2 has transformed from rhombohedra system to hexagonal system.
Key words: Li0.5Na0.5CoO2; electron diffraction; crystal structure; synthesis
