X-ray absorption spectroscopy studies of Ca 2.9Ln 0.1Co 4O 9+δ (Ln = Ca, Dy, Ho, Er and Lu)

J. L. Chen, Y. S. Liu, Chia-Jyi Liu, N. V. Nong, Y. C. Kao, C. C. Chen, W. C. Wang, S. S. Chen, C. L. Chen, C. L. Dong, C. L. Chang

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Abstract

X-ray absorption near edge structure (XANES) study of Co K-, Co L 2,3-, O K-, and Ca L 2,3-edges on a series of polycrystalline Ca 2.9Ln 0.1Co 4O 9+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 L 2,3-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 Co 4+ 3d-O 2p hybridized unoccupied states also show an opposite trend, which is consistent with our results that a lesser amount of Co 4+ leads to a larger thermoelectric power. There is a monotonic decrease of Ca L 2,3-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.

Original languageEnglish
Pages (from-to)8-11
Number of pages4
JournalJournal of Alloys and Compounds
Volume529
DOIs
Publication statusPublished - 2012 Jul 15

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X ray absorption spectroscopy
Thermoelectric power
X ray absorption
Doping (additives)

All Science Journal Classification (ASJC) codes

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

Cite this

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. / X-ray absorption spectroscopy studies of Ca 2.9Ln 0.1Co 4O 9+δ (Ln = Ca, Dy, Ho, Er and Lu). In: Journal of Alloys and Compounds. 2012 ; Vol. 529. pp. 8-11.
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title = "X-ray absorption spectroscopy studies of Ca 2.9Ln 0.1Co 4O 9+δ (Ln = Ca, Dy, Ho, Er and Lu)",
abstract = "X-ray absorption near edge structure (XANES) study of Co K-, Co L 2,3-, O K-, and Ca L 2,3-edges on a series of polycrystalline Ca 2.9Ln 0.1Co 4O 9+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 L 2,3-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 Co 4+ 3d-O 2p hybridized unoccupied states also show an opposite trend, which is consistent with our results that a lesser amount of Co 4+ leads to a larger thermoelectric power. There is a monotonic decrease of Ca L 2,3-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.",
author = "Chen, {J. L.} and Liu, {Y. S.} and Chia-Jyi Liu and Nong, {N. V.} and Kao, {Y. C.} and Chen, {C. C.} and Wang, {W. C.} and Chen, {S. S.} and Chen, {C. L.} and Dong, {C. L.} and Chang, {C. L.}",
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Chen, JL, Liu, YS, Liu, C-J, Nong, NV, Kao, YC, Chen, CC, Wang, WC, Chen, SS, Chen, CL, Dong, CL & Chang, CL 2012, 'X-ray absorption spectroscopy studies of Ca 2.9Ln 0.1Co 4O 9+δ (Ln = Ca, Dy, Ho, Er and Lu)', Journal of Alloys and Compounds, vol. 529, pp. 8-11. https://doi.org/10.1016/j.jallcom.2012.03.052

X-ray absorption spectroscopy studies of Ca 2.9Ln 0.1Co 4O 9+δ (Ln = Ca, Dy, Ho, Er and Lu). / 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.

In: Journal of Alloys and Compounds, Vol. 529, 15.07.2012, p. 8-11.

Research output: Contribution to journalArticle

TY - JOUR

T1 - X-ray absorption spectroscopy studies of Ca 2.9Ln 0.1Co 4O 9+δ (Ln = Ca, Dy, Ho, Er and Lu)

AU - Chen, J. L.

AU - Liu, Y. S.

AU - Liu, Chia-Jyi

AU - Nong, N. V.

AU - Kao, Y. C.

AU - Chen, C. C.

AU - Wang, W. C.

AU - Chen, S. S.

AU - Chen, C. L.

AU - Dong, C. L.

AU - Chang, C. L.

PY - 2012/7/15

Y1 - 2012/7/15

N2 - X-ray absorption near edge structure (XANES) study of Co K-, Co L 2,3-, O K-, and Ca L 2,3-edges on a series of polycrystalline Ca 2.9Ln 0.1Co 4O 9+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 L 2,3-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 Co 4+ 3d-O 2p hybridized unoccupied states also show an opposite trend, which is consistent with our results that a lesser amount of Co 4+ leads to a larger thermoelectric power. There is a monotonic decrease of Ca L 2,3-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.

AB - X-ray absorption near edge structure (XANES) study of Co K-, Co L 2,3-, O K-, and Ca L 2,3-edges on a series of polycrystalline Ca 2.9Ln 0.1Co 4O 9+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 L 2,3-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 Co 4+ 3d-O 2p hybridized unoccupied states also show an opposite trend, which is consistent with our results that a lesser amount of Co 4+ leads to a larger thermoelectric power. There is a monotonic decrease of Ca L 2,3-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.

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U2 - 10.1016/j.jallcom.2012.03.052

DO - 10.1016/j.jallcom.2012.03.052

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SN - 0925-8388

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