Thermoelectric properties and electronic structure of Ca₃Co₂O₆

Abstract

The nanosized Ca₃Co₂O₆ powder was synthesized via sol-gel process. The phase composition was characterized by means of X-ray diffraction. Polycrystalline samples of Ca₃Co₂O₆ were prepared by a sintering procedure of nanosized power. The seebeck coefficient and electrical conductivity of the samples were measured from 450K up to 750K. The results show that the Seebeck coefficient increases with the increasing temperature. The electronic structures were calculated using the self-consistent full-potential linearized augmented plane-wave (LAPW) method within the density functional theory. The relationship between thermoelectric property and electronic structures was discussed.

Keywords

thermoelectric property / electronic structure / nanosized compounds

References

[1] Sasago T Y, Uchinokura K. Large Thermoeletric Power in NaCo₂O₄ Signgle Crystals. Phys. Rev., 1997, 56(20): 12685-12687.

[2] Helmer F, Egil G, Siv A, . Crystal Structure and Possible Charge Ordering in One-dimensional Ca₃Co₂O₆. J. Solid State Chem., 1996, 124: 190-190.

[3] Vidyasager K. A Convenient Route for the Synthesis of Complex Metal Oxides Employing Solid-solution Precursors. Inorg Chem., 1984, 23: 1206-1210.

[4] Cronin S B, Koga T, Sun X, Ding Z, . Approaches toward Chemically Prepared Multiple Quantum Well Structures. Mat. Res. Soc. Sym. Proc., 1998, 545: 397-397.

[5] Singh D. Planewaves, Pseudopotentials, 1994 Boston: Kluwer Academic. 50-80.

[6] Ji-ming An, Ce-wen Nan, Sheng-li Chen. The Calculation of Energy Bands by Using LAPW Method. Journal of Wuhan University of Technology-Mater. Sci. Ed., 2002, 24(7): 9-9. (in Chinese)

[7] Singh D J, Pickett W E. Skutterudite Antimonides: Quasilliner Bands and Unussal Transport. Phys. Rev., 1994, 50(15): 11235-11238.

[8] Seeger K. Semi-conductor Physics, 1980 Beijing: People Education Press. 197-204. (In Chinese)