Title :
Electrical conductivity and CO gas sensitivity of ZnO-TiO2 composites
Author :
Kim, Tae-Won ; Choi, U-Sung ; Jung, Seung-Woo
Author_Institution :
Dept. of Electron. Mater. Eng., WonKwang Univ., Iksan, South Korea
Abstract :
Using complex impedance measurement, a voltage-current source and measurement unit, the AC and DC characteristics of ZnO-TiO2 composites are investigated. The electrical conductivity increase with increasing TiO2 content was explained by the connectivity of ZnO and TiO2 grains. Compared with pure and ball-milled ZnO, the electrical conductivity of TiO2 added ZnO in the impedance spectrum is four orders of magnitude smaller. The calculated relative dielectric constants for the 3, 5, and 7 mol% TiO2 added ZnO are 7, 13, and 120, respectively. Compared with the relative dielectric constant of ZnO, the semicircle of 3 mol% TiO2 added ZnO seems to be the ZnO grain. The sizes of the semicircle decrease with increasing TiO2 content. These results are consistent with the trends of DC conductivity
Keywords :
II-VI semiconductors; ceramics; composite materials; dielectric losses; electric impedance; electrical conductivity; gas sensors; grain boundaries; permittivity; titanium compounds; zinc compounds; AC characteristics; CO; CO gas sensitivity; DC characteristics; TiO2 content dependence; ZnO; ZnO-TiO2; ZnO-TiO2 composites; complex impedance measurement; dielectric loss factor; electrical conductivity; relative dielectric constants; semicircle; voltage-current source; Atom optics; Conductivity; Electrical resistance measurement; Electrons; Grain size; Impedance measurement; Measurement units; Microstructure; Ultrasonic variables measurement; Zinc oxide;
Conference_Titel :
Properties and Applications of Dielectric Materials, 1997., Proceedings of the 5th International Conference on
Conference_Location :
Seoul
Print_ISBN :
0-7803-2651-2
DOI :
10.1109/ICPADM.1997.616569
