Defect chemistry of lithium-doped magnesium oxide

被引:14
作者
Balint, I [1 ]
Aika, K [1 ]
机构
[1] INTERDISCIPLINARY GRAD SCH SCI & TECHNOL,DEPT ENVIRONM CHEM & ENGN,MIDORI KU,YOKOHAMA,KANAGAWA 226,JAPAN
来源
JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS | 1997年 / 93卷 / 09期
关键词
D O I
10.1039/a607337i
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The dc conductivity of lithium-doped magnesium oxide has been measured, as a function of water vapour and oxygen partial pressure, using the four-point probe method. Proton species were found to dominate the conduction mechanism at low temperatures (673 K); increase in temperature (773-973 K) led to a mixed conduction mechanism: i.e. by protons and by holes (p-type conductivity). In the high-temperature region (1073-1173 K) 1% Li/MgO shows only p-type conduction, the proton contribution to the overall conductivity being negligible. Defect chemistry equations were used to describe the mechanism of formation of hydrogen and hole defects. The proposed mechanism assumes oxygen vacancies, created by lithium doping, play a crucial role in O- site generation. At low temperatures, the oxygen vacancies are blocked by hydrogen defects; as the temperature increases, the free oxygen vacancies created can interact with gas-phase oxygen and generate O- sites (holes).
引用
收藏
页码:1797 / 1801
页数:5
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