Dopant Effects to Pores in ZnO Varistors

Author

Tu, Youping ; Ding, Lijian ; He, Jinliang ; Hu, Jun ; Han, Se-Won ; Cho, Han-Goo

Author_Institution

Dept. of Electr. Eng., North China Electr. Power Univ., Beijing

fYear

2006

fDate

38869

Firstpage

967

Lastpage

970

Abstract

Pore is an intrinsic property of ZnO varistor. There are two different shapes of pores in ZnO varistor samples, one is sphere shape, and another is irregular polyhedron. Pores are caused by air particles wrapped in initial varistor compact and grains-surrounded spaces during the sintering. By analyzing the pore phenomena in two different systems of ZnO varistors, we observed the pore ratio decreases, pores with large size are formed, and the pores inside ZnO grains decreases with the increase of the amount of Al₂O₃ additives, which are caused by the pinning effect of spinel formed by additives. The pores are possibly related to grain growth inhibition by dragging effects

Keywords

II-VI semiconductors; alumina; grain growth; grain size; sintering; varistors; zinc compounds; ZnO:Al₂O₃; air particles; dopant effects; dragging effects; grain growth; intrinsic property; pinning effect; pore phenomena; pore ratio; sintering; sphere shape; varistors; Additives; Electric variables; Grain boundaries; Powders; Power system protection; Scanning electron microscopy; Shape; Varistors; Voltage control; Zinc oxide; ZnO varistor; additive; intrinsic property; pore;

fLanguage

English

Publisher

ieee

Conference_Titel

Properties and applications of Dielectric Materials, 2006. 8th International Conference on

Conference_Location

Bali

Print_ISBN

1-4244-0189-5

Electronic_ISBN

1-4244-0190-9

Type

conf

DOI

10.1109/ICPADM.2006.284339

Filename

4062828