Title :
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
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;
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
DOI :
10.1109/ICPADM.2006.284339
