Effect of Thermal Annealing on Electrical Degradation Characteristics of Sb2O3-Bi-Mn-Co-Doped ZnO Varistors

Abstract:

Article Preview

The effects of thermal annealing on the electrical degradation of Sb2O3-Bi-Mn-Co-doped ZnO varistors were investigated. For samples with 0.04 mol% Sb2O3 or more, the nonlinearity index  of the voltage-current (V-I) characteristics after electrical degradation increased upon annealing. More-over, the value of  after electrical degradation was proportional to the full width at half maximum (FWHM) of the X-ray diffraction peak for Zn2.33Sb0.67O4-type spinel particles under various annealing conditions. The added Sb2O3 did not dissolve in the ZnO grains but became segregated at grain boundaries. Therefore, it is speculated that the increase in the FWHM of the spinel particles is due to an increase in the numbers of fine spinel particles at grain boundaries and triple points during annealing. Furthermore, it is suggested that the improvement in the electrical degradation upon annealing is due to a decrease in the mobility of oxide ions or Zn2+ ions owing to their being blocked by uniformly distributed fine spinel particles at grain boundaries.

Info:

Periodical:

Key Engineering Materials (Volumes 421-422)

Edited by:

Tadashi Takenaka, Hajime Haneda, Kazumi Kato, Masasuke Takata and Kazuo Shinozaki

Pages:

525-528

DOI:

10.4028/www.scientific.net/KEM.421-422.525

Citation:

M. Takada et al., "Effect of Thermal Annealing on Electrical Degradation Characteristics of Sb2O3-Bi-Mn-Co-Doped ZnO Varistors", Key Engineering Materials, Vols. 421-422, pp. 525-528, 2010

Online since:

December 2009

Export:

Price:

$35.00

In order to see related information, you need to Login.