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钙钛矿陶瓷La1-xCaxMnO3 (x=0.10, 0.15, 0.20)的光电子能谱

DOI: 10.7521/j.issn.0454-5648.2014.07.08

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Abstract:

对溶胶凝胶法制备的钙掺杂LaMnO3多晶陶瓷材料La1-xCaxMnO3(x=0.10,0.15,0.20)进行了X射线衍射和各个元素的光电子能谱研究,其X射线衍射实验表明该系列样品表现出很好的单相性,其空间结构为正交型Pbnm。Mn2p,La4d,O1s能级的光电子能谱结果表明当掺杂浓度较低时,Ca离子在La位的掺杂不会引起La和O元素电子组态的变化,只引起Mn离子的化学价态变化。利用组态相互作用团簇模型计算了Mn2p光电子能谱,得到晶体场分裂能10Dq=1.0eV,电荷转移能Δ=5eV,d轨道之间的库伦排斥能Udd=4eV,pd轨道之间的库伦排斥能Upd=4.4eV,过渡金属离子d轨道和近邻O离子之间的轨道杂化能T(eg)=3.8eV。

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