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 language | English |
|---|---|
| Pages (from-to) | 8-11 |
| Number of pages | 4 |
| Journal | Journal of Alloys and Compounds |
| Volume | 529 |
| DOIs | |
| Publication status | Published - 2012 Jul 15 |
Fingerprint
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry
Cite this
}
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 journal › Article
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.
UR - http://www.scopus.com/inward/record.url?scp=84859480423&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84859480423&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2012.03.052
DO - 10.1016/j.jallcom.2012.03.052
M3 - Article
AN - SCOPUS:84859480423
VL - 529
SP - 8
EP - 11
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
ER -