Abstract
The correlation between the p-type hole conduction and the electronic structures of Cr-deficient CuCr 1-x O 2 (x=0-0.1) compounds was investigated using O K-, Cu, and Cr L 3,2 -edge x-ray absorption near-edge structure (XANES), scanning photoelectron microscopy, and x-ray emission spectroscopy measurements. XANES spectra reveal a gradual increase in the Cu valence from Cu1 + to Cu2 + with increasing Cr deficiency x, whereas, the valence of Cr remains constant as Cr3 + . These results indicate that the p-type conductivity in the CuCr 1-x O 2 samples is enhanced by a Cu1 + -O-Cu2 + rather than a Cr3 + -Cr4 + or direct Cu1 + -Cu2 + hole mechanism. Remarkable Cr-deficiency-induced changes in the densities of Cu 3d, Cu 3d-O 2p, and O 2p states at or near the valence-band maximum or the Fermi level were also observed. In addition, a crossover of conduction mechanism from thermally activated (TA) hopping to a combination of TA and Mott's three-dimensional variable range hopping occurs around 250 K.
| Original language | English |
|---|---|
| Article number | 241103 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 86 |
| Issue number | 24 |
| DOIs | |
| Publication status | Published - 2012 Dec 7 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
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Correlation between p-type conductivity and electronic structure of Cr-deficient CuCr 1-x O 2 (x = 0 - 0.1) . / Singh, Shashi B.; Yang, L. T.; Wang, Y. F.; Shao, Y. C.; Chiang, C. W.; Chiou, J. W.; Lin, K. T.; Chen, S. C.; Wang, Bo-Yao; Chuang, C. H.; Ling, D. C.; Pong, W. F.; Tsai, M. H.; Tsai, H. M.; Pao, C. W.; Shiu, H. W.; Chen, C. H.; Lin, H. J.; Lee, J. F.; Yamane, H.; Kosugi, N.
In: Physical Review B - Condensed Matter and Materials Physics, Vol. 86, No. 24, 241103, 07.12.2012.Research output: Contribution to journal › Article
TY - JOUR
T1 - Correlation between p-type conductivity and electronic structure of Cr-deficient CuCr 1-x O 2 (x = 0 - 0.1)
AU - Singh, Shashi B.
AU - Yang, L. T.
AU - Wang, Y. F.
AU - Shao, Y. C.
AU - Chiang, C. W.
AU - Chiou, J. W.
AU - Lin, K. T.
AU - Chen, S. C.
AU - Wang, Bo-Yao
AU - Chuang, C. H.
AU - Ling, D. C.
AU - Pong, W. F.
AU - Tsai, M. H.
AU - Tsai, H. M.
AU - Pao, C. W.
AU - Shiu, H. W.
AU - Chen, C. H.
AU - Lin, H. J.
AU - Lee, J. F.
AU - Yamane, H.
AU - Kosugi, N.
PY - 2012/12/7
Y1 - 2012/12/7
N2 - The correlation between the p-type hole conduction and the electronic structures of Cr-deficient CuCr 1-x O 2 (x=0-0.1) compounds was investigated using O K-, Cu, and Cr L 3,2 -edge x-ray absorption near-edge structure (XANES), scanning photoelectron microscopy, and x-ray emission spectroscopy measurements. XANES spectra reveal a gradual increase in the Cu valence from Cu1 + to Cu2 + with increasing Cr deficiency x, whereas, the valence of Cr remains constant as Cr3 + . These results indicate that the p-type conductivity in the CuCr 1-x O 2 samples is enhanced by a Cu1 + -O-Cu2 + rather than a Cr3 + -Cr4 + or direct Cu1 + -Cu2 + hole mechanism. Remarkable Cr-deficiency-induced changes in the densities of Cu 3d, Cu 3d-O 2p, and O 2p states at or near the valence-band maximum or the Fermi level were also observed. In addition, a crossover of conduction mechanism from thermally activated (TA) hopping to a combination of TA and Mott's three-dimensional variable range hopping occurs around 250 K.
AB - The correlation between the p-type hole conduction and the electronic structures of Cr-deficient CuCr 1-x O 2 (x=0-0.1) compounds was investigated using O K-, Cu, and Cr L 3,2 -edge x-ray absorption near-edge structure (XANES), scanning photoelectron microscopy, and x-ray emission spectroscopy measurements. XANES spectra reveal a gradual increase in the Cu valence from Cu1 + to Cu2 + with increasing Cr deficiency x, whereas, the valence of Cr remains constant as Cr3 + . These results indicate that the p-type conductivity in the CuCr 1-x O 2 samples is enhanced by a Cu1 + -O-Cu2 + rather than a Cr3 + -Cr4 + or direct Cu1 + -Cu2 + hole mechanism. Remarkable Cr-deficiency-induced changes in the densities of Cu 3d, Cu 3d-O 2p, and O 2p states at or near the valence-band maximum or the Fermi level were also observed. In addition, a crossover of conduction mechanism from thermally activated (TA) hopping to a combination of TA and Mott's three-dimensional variable range hopping occurs around 250 K.
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U2 - 10.1103/PhysRevB.86.241103
DO - 10.1103/PhysRevB.86.241103
M3 - Article
VL - 86
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 1098-0121
IS - 24
M1 - 241103
ER -