Electric properties of [(ZrO{sub 2}){sub 0.8}(CeO{sub 2}){sub 0.2}]{sub 0.9}(CaO){sub 0.1} solid solution
- Tohoku Univ., Sendai (Japan). Research Inst. for Scientific Measurements
The oxygen nonstoichiometry, the total conductivity, and the electronic conductivity of [(ZrO{sub 2}){sub 0.8}(CeO{sub 2}){sub 0.2}]{sub 0.9}(CaO){sub 0.1} were measured by using high temperature gravimetry, dc four-terminal method, and Hebb-Wagner`s dc polarization technique, respectively. The change in the oxygen nonstoichiometry was explained by assuming Ce{prime}{sub Zr}, Ca{double_prime}{sub Zr}, and V{sup {sm_bullet}{sm_bullet}}{sub O} as major defects. At 1,173 K and p{sub O{sub 2}} = 1 {times} 10{sup {minus}11} atm, the total conductivity corresponded to the ionic conductivity is proportional to [V{sup {sm_bullet}{sm_bullet}}{sub O}]. At the lower p{sub O{sub 2}}, although the oxygen vacancy increased with the decreasing p{sub O{sub 2}}, the ionic conductivity decreased. The relation between [V{sup {sm_bullet}{sm_bullet}}{sub O}] and the ionic conductivity was similar to that in stabilized ZrO{sub 2} with various CaO contents. It was shown that the electronic conductivity is proportional to [Ce{sub Zr}{sup {prime}}], which is not in accordance with the hopping-type conduction between Ce{sup 3+} and Ce{sup 4+}. Assuming all Ce{prime}{sub Zr} release conduction electrons, the calculated mobility is in the order of 10{sup {minus}6} cm{sup 2}/V s at 1,173 K and does not correspond to the band conduction model. It was considered that most of the electrons are trapped at the donor level formed by Ce{prime}{sub Zr} and only a small portion of the electrons is excited to conduction band as carriers.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 653392
- Journal Information:
- Journal of the Electrochemical Society, Vol. 145, Issue 7; Other Information: PBD: Jul 1998
- Country of Publication:
- United States
- Language:
- English
Similar Records
Microstructure and electrical transport in nano-grain sized Ce{sub 0.9}Gd{sub 0.1}O{sub 2-{delta}} ceramics
Defect clustering and related properties of oxides