X-ray absorption spectroscopy studies of Ca2.9Ln0.1Co4O9+δ (Ln = Ca, Dy, Ho, Er and Lu)
學年 100
學期 2
出版（發表）日期 2012-07-01
作品名稱 X-ray absorption spectroscopy studies of Ca2.9Ln0.1Co4O9+δ (Ln = Ca, Dy, Ho, Er and Lu)
作品名稱（其他語言）
著者 Chen, J.L.; Liu, Y.S.; Liu, Chia-Jyi; Nong, N.V.; Kao, Y.C.; Chen, C.C.; Wang, W.C.; Chen, S.S.; Chen, C.L.; Dong, C.L.; Chang, C.L.
單位 淡江大學物理學系暨研究所
出版者 Amsterdam: Elsevier BV
著錄名稱、卷期、頁數 Journal of Alloys and Compounds 529, pp.8-11
摘要 X-ray absorption near edge structure (XANES) study of Co K-, Co L2,3-, O K-, and Ca L2,3-edges on a series of polycrystalline Ca2.9Ln0.1Co4O9+δ (Ln = Ca, Dy, Ho, Er and Lu) are presented. The high similarity of Co K-edge spectra of the doped and the undoped samples indicate that the average valence of Co is slightly higher than 3+ and it is not varied for different dopants. The variation of the intensity of the Co L2,3-edge indicates that the number of Co 3d unoccupied states and thermoelectric power shows an opposite trend. According to the O K-edge spectra, the electrical resistivity and Co4+3d–O 2p hybridized unoccupied states also show an opposite trend, which is consistent with our results that a lesser amount of Co4+ leads to a larger thermoelectric power. There is a monotonic decrease of Ca L2,3-edge intensity with decreasing ionic radius of the Ln element, which partially substituted for Ca. This could be attributed to a decrease of Ca 3d–O 2p hybridization with decreasing ionic radius of Ln.
關鍵字 Thermoelectric materials; X-ray absorption spectroscopy; Thermoelectric power; Cobaltite
語言 en_US
ISSN 0925-8388
期刊性質 國外
收錄於
產學合作
通訊作者
審稿制度
國別 NLD
公開徵稿
出版型式 紙本
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