Electrical Properties and Defect Types of Nb-doped <TEX>$TiO_2$</TEX>

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J. Korean Ceram. Soc. > Volume 36(12); 1999 > Article

Journal of the Korean Ceramic Society 1999;36(12): 1335.

Nb를 첨가한 $TiO_2$ 의 전기적 성질 및 결함형태

이순일, 백승봉, 김명호

창원대학교 세라믹공학과

Electrical Properties and Defect Types of Nb-doped $TiO_2$

ABSTRACT

The electrical conductivity ($sigma$) of TiO2 doped with 0.05-4.0mol% Nb2O5 was measured in the oxygen partial pressure range of 10-17 to 100 atm and temperature range of 1100 to 130$0^{circ}C$ to investigate the electrical properties and defect types. The oxygen partial pressure dependence of the electrical conductivity (log$sigma$/logPo2) above 110$0^{circ}C$ was divided into the four regions. From these experimental results the following defect regions were proposed ; 1) Magneli phase(extended defect) 2) reduced rutile region where intrinsic defect predominates 3) nearly stoichiometric region which is independent on the oxygen partical pressure and 4) overstoichiometric region which is not observed in pure TiO2 The electrical conductivity of Nb-doped TiO2 depended on the doping content the oxygen partial pressure and the measuring tem-perature.

Key words: $TiO_2$, $Nb_2O_5$, Defect types, Electrical conductivity, Charge campensation