Electronic structure and thermoelectric properties of Ca3Co4O9

Min Xinmin; Xing Xueling

doi:10.1007/BF02861459

Journal of Wuhan University of Technology Materials Science Edition ›› 2006, Vol. 21 ›› Issue (1) : 13 -15. DOI: 10.1007/BF02861459

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Electronic structure and thermoelectric properties of Ca₃Co₄O₉

Min Xinmin ¹^,^a
, Xing Xueling ¹^,²

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Abstract

The relation among electronic structure., chemical bond and thermoelectric property of Ca₃ C0₄ O₉ was studied using density function and discrete variation method (DFTDVM). The gap between the highest valence band (HVB) and the lowest conduction band (LCB) shows a semiconducting property. Ca₃ Co₄ O₉ consists of CoO₂ and Ca₂ CoO₃ two layers. The HVB and LCB near Fermi level are only mainly from O(2) 2_p and Co (2) 3d in Ca₂CoO₃ layer. Therefore, the semiconducting or thermoelectric property of Ca₃ Co₄ O₉ should be mainly from Ca₂ CoO₃ layer, but it seems to have no direct relation to the CoO₂ layer, which is consistent with that binary oxides hardly have a thermoelectric property, but trinary oxide compounds have quite a good thermoelectric property. The covalent and ionic bonds of Ca₂ CoO₃ layer are both weaker than those of Co0₂ layer. Ca plays the role of connections between CoO₂ and Ca2 CoO₃ layers in Ca₃ CO₄ O₉, decrease the ionic and covalent bond strength, and improve the thermoelectric property.

Keywords

cobaltite / electronic structure / chemical bond / thermoelectric property

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Min Xinmin, Xing Xueling. Electronic structure and thermoelectric properties of Ca₃Co₄O₉. Journal of Wuhan University of Technology Materials Science Edition, 2006, 21(1): 13-15 DOI:10.1007/BF02861459

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References

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[1]	Sasago T Y, Uohinokura K. Large Thermoeletric Power in NaCo₂ O₄ Single Crystals. Phys. Rev. B, 1997, 56: 12685-12685.

[2]	Asahi R, Sungiyama J, Tani T. Electronic Structure of Misfit-layered Calcium Cobaltite. Phys. Rev. B, 2002, 66: 1551031-1551031.

[3]	Shen-xiou Xiao, Cong-yu Wang, Tian-lang Chen. The Method of Density Function and Discrete Variation Used in Chemistry and Material Physics, 1998 Beijing: Science Press.

[4]	Xin-min Min, Rui-Juan Xiao, Hao Wang, Wei-min Wang. Electronic Structure and Chemical Bond of Titanium Diboride. J. Wuhan Uni. Tech. Mat.-Sci. Ed., 2003, 18(2): 11-11.

[5]	Xin-min MIN, Rui-juan Xiao, Hanlie Hong. Quantum Chemistry Calculation on Oxygen and Nitrogen Adsorption in Carbon Nanotude. J. Wuhan Uni. Tech.-Mat. Sci. Ed., 2003, 18(1): 1-1.

[6]	Miyazaki Y, Onoda M, Oku T., . Modulated Structure of the Thermoelectric Compound [Ca₂CoO₃]_0.62CoO₂. J. Phys. Soc. Japan, 2002, 71: 491-491.