Electronic structure and metal-insulator transition in LaNiO3-δ -: art. no. 155101
Electronic structure and metal-insulator transition in LaNiO3-δ -: art. no. 155101
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DOI：
10.1103/physrevb.65.155101
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发表时间：
2002-04-15
影响因子：
3.7
通讯作者：
Vallet-Regi, M
中科院分区：
文献类型：
--
作者：
Abbate, M;Zampieri, G;Vallet-Regi, M
我们研究了LaNiO 3-delta在金属-绝缘体转变过程中电子结构的变化。研究中使用的技术主要是O 1 s X射线吸收光谱（XAS）。用团簇模型计算了LaNiO3.00的实验光谱。LaNiO 3.00的光谱在对应于3d（8）（L）的阈值处呈现尖锐的峰，在3d（9）条下的条->（C）。对该峰的分析表明，LaNiO 3.00中的电荷载流子含有相当大的氧特征。该峰的强度在LaNiO 2.75的光谱中降低，并且对于LaNiO 2.50几乎完全消失。这表明金属-绝缘体转变与电荷载流子的消失和随后的带隙开放有关。在LaNiO2.75化合物的峰分裂，由于存在两个不等价的结晶位点。该化合物中的金属-绝缘体转变初步归因于这两个位置之间的潜在无序。
We studied the changes in the electronic structure of LaNiO3-delta across the metal-insulator transition. The technique used in the study was mainly O 1s x-ray absorption spectroscopy (XAS). The experimental spectrum of LaNiO3.00 was analyzed in terms of a cluster-model calculation. The spectrum of LaNiO3.00 presents a sharp peak at a threshold that corresponds to 3d(8)(L) under bar --> (C) under bar 3d(9) transitions. Analysis of this peak indicates that the charge carriers in LaNiO3.00 contain considerable oxygen character. The intensity of this peak decreases in the spectrum of LaNiO2.75 and disappears almost completely for LaNiO2.50. This suggests that the metal-insulator transition is related to the disappearance of the charge carriers and the ensuing band-gap opening. The peak in the LaNiO2.75 compound is split due to the presence of two nonequivalent crystallographic sites. The metal-insulator transition in this compound is tentatively attributed to potential disorder between these two sites.