한국세라믹학회지 (Journal of the Korean Ceramic Society)

  • 제46권6호
  • /
  • Pages.689-694
  • /
  • 2009
  • /
  • 1229-7801(pISSN)
  • /
  • 2234-0491(eISSN)
한국세라믹학회 (The Korean Ceramic Society)
권호 표지
DOI QR코드

DOI QR Code

NaxCo2O4의 열전특성에 미치는 Na 함량변화와 첨가제의 효과

Determination of the Thermolelectric Properties of NaxCo2O4 by Controlling the Concentration of Na and Additive

  • Choi, Soon-Mok (Korea Institute of Ceramic Engineering and Technology(KICET)) ;
  • Jeong, Seong-Min (Korea Institute of Ceramic Engineering and Technology(KICET)) ;
  • Seo, Won-Seon (Korea Institute of Ceramic Engineering and Technology(KICET))
  • 발행 : 2009.11.30
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

Layer-structured $Na_xCo_2O_4$ was synthesized from $Na_2CO_3\;and\;Co_3O_4$ powders. The chemical concentrations of Na and additive were controlled to enhance the thermoelectric properties over the temperature range from 400 K to 1,150 K. As a result, we obtained the maximum thermoelectric properties at a single phase region with Na content of x=1.5. When Na content was smaller than x=1.5, the thermoelectric properties was low due to formation of second phases of CoO and other oxides. Additionally, Mn was doped to improve thermoelectric properties by means of decreasing thermal conductivity. The results showed that the concentrations of both Na and Mn are all governing factors to determine the thermoelectric properties of $Na_xCo_2O_4$ system.

키워드

참고문헌

  1. I. Terasaki, Y. Sasago, and K. Uchinokura, “Large Thermoelectric Power in $NaCo_2O_4$ Single Crystals,” Phys. Rev. B, 56 R12685-87 (1997) https://doi.org/10.1103/PhysRevB.56.R12685
  2. T. Motohashi, E. Naujalis, R. Ueda, K. Isawa, M. Karppinen, and H. Yamauchi, “Simultaneously Enhanced Thermoelectric Power and Reduced Resistivity of $Na_xCo_2O_4$ by Controlling Na Nonstoichiometry,” Applied Physics Letters, 79 [10] 1480-82 (2001) https://doi.org/10.1063/1.1400777
  3. C. Fouassier, G. Matejka, J.-M. Reau, and P. Hagenmuller, “Sur De Nouveaux Bronzes Oxygenes De Formule $NaxCoO_2$ Le Systeme Cobalt-oxyegne-sodium,” J. Solid State Chem., 6 532-37 (1973) https://doi.org/10.1016/S0022-4596(73)80011-8
  4. Z. P. Guo, Y. G. Zhao, W. Y. Zhang, L. Cui, S. M. Guo, and L. B. Luo, “Effect of Ga and Mn Doping on Structural, Electrical Transport and Magnetic Properties of $Na_{0.75}CoO_2$,” J. Physics :Condensed Matter, 18 4381-88 (2006) https://doi.org/10.1088/0953-8984/18/17/023
  5. P. Strobela, H. Muguerraa, S. Hebertb, E. Pachouda, C. Colina, and M. Julienc, “Effect of Ruthenium Substitution in Layered Sodium Cobaltate $NaxCoO_2$: Synthesis, Structural and Physical Properties,” J. Solid State Chemistry, 182 1872-78 (2009) https://doi.org/10.1016/j.jssc.2009.04.030
  6. K. Takada, H. Sakurai, E. Muromachi, F. Izumi, R. A. Dilanian, and T. Sasaki, “Superconductivity in Two-dimensional $CoO_2$ layers,” Nature, 422 53-5 (2003) https://doi.org/10.1038/nature01450