Electrical Conductivity of the System NiO-$Y_2O_3$

NiO-$Y_2O_3$계의 전기전도성

  • Jae Shi Choi (Department of Chemisrty, College of Science, Yonsei University) ;
  • Keu Hong Kim (Department of Chemisrty, College of Science, Yonsei University) ;
  • Won Yang Chung (Department of Chemistry, College of Natural Science, Kangwon National University)
  • 최재시 (연세대학교 이과대학 화학과) ;
  • 김규홍 (연세대학교 이과대학 화학과) ;
  • 정원양 (강원대학교 자연과학대학 화학과)
  • Published : 1986.02.20

Abstract

Electrical conductivities of NiO-$Y_2O_3$ systems containing 0.8, 1.6, and 3.2 mol% NiO have been measured in the temperature range of 400 to 1100$^{\circ}$C at $PO_2$'s of 1 ${\times}10^{-5}$ to 2 ${\times}10^{-1}$ atm. Plots of $log\sigma$ vs 1/T at constant $PO_2$'s are found to be linear with an inflection at temperature around 650$^{\circ}$C. The slopes are steeper in the high temperature region above 650$^{\circ}$C than in the low temperature region below 650$^{\circ}$C. The average activation energies are 41.8kcal/mol in the high temperature region and 12.5kcal/mol in the low temperature region. $PO_2$'s dependence value, 1/n, is 1/5.1~1/5.4 in the high temperature region and 1/5.9~1/6.2 in the low temperature region. The NiO-$Y_2O_3$ systems are found to be an electronic p-type semiconductor. The predominant defects in the systems are believed to be triply ionized yttrium vacancy in the high temperature region and doubly ionized oxygen interstitial in the low temperature region. Ionic contribution to the total conductivity is found from ${\sigma}^{\propto}PO_2$ in the temperatures below 650$^{\circ}$C.

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References

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