钴基掺杂氧化物结构特征的研究  

THE STUDY OF STRUCTURAL FEATURES IN DOPED CO-BASED OXIDES SYSTEM

作　　者：吴成国[1] 董秋云[1] 何苏红[1] 杜华月[1] 陈磊[1] 

机构地区：[1]解放军理工大学理学院,南京210007

出　　处：《低温物理学报》2009年第3期221-224,共4页Low Temperature Physical Letters

基　　金：国家科技部(项目编号:NKBRSG-G1999064602)~~

摘　　要：利用溶胶-凝胶(sol-gel)法制备出了一系列La0.8Sr0.2Co1-xFexO3样品.xRD结果显示,在La0.8Sr0.2Co1-xFexO3系列样品中,未掺杂的La0.8Sr0.2CoO3样品具有很好的单相结构,并且衍射峰没有发生劈裂;而Fe掺杂的La0.8Sr0.2CoO3样品中几乎每个衍射峰都发生了劈裂,在Fe掺杂的La0.8Sr0.2CoO3样品中可能存在两种不同的晶体结构.利用xANES研究了La0.8Sr0.2Co1-xFexO3样品中Co离子和Fe离子的化合价发现,Fe离子存在两种不同的化合价态,即Fe3+和Fe4+离子,在La0.8Sr0.2Co1-xFexO3样品中形成了两个不同离子的富集区,一个是由Co3+、Co4+和Fe3+等离子组成的,一个是由Fe4+和Co3+、Co4+等离子组成的,因此在Fe掺杂的La0.8Sr0.2CoO3样品中存在两种不同的晶体结构.The polycrystalline samples of La0.8Sr0.2Co1-xFexO3 were prepared by the sol-gel method, xRD shows that inLa0.8Sr0.2Co1-xFexO3 system the undoped La0.8Sr0.2CoO3 sample has a single phase, and the diffraction peaks do not split; but in Fe-doped La0.8Sr0.2CoO3 samples almost all of the diffraction peaks are splitted, implying that there are probably two different crystal structures in Fe-doped La0.8Sr0.2CoO3 samples. The results of xANES indicate that Fe ions have two different valences such as Fe^3＋ and Fe^4＋ ions in La0.8Sr0.2Co1-xFexO3 system. The results also reflect two different ions-rich areas in La0.8Sr0.2Co1-xFexO3 samples： one includes Co^3＋ , Co^4＋ , Fe^3＋ ions, and another includes Co^3＋ , Co^4＋ , Fe^4＋ ions. Thus it induces two different crystal structures in Fe-doped La0.8Sr0.2CoO3samples.

关 键 词：XANES 劈裂 化合价 溶胶-凝胶 

分 类 号：O483[理学—固体物理]