Title :
Influence of pre-synthetic spinels on electrical properties of ZnO varistors
Author :
Qing, Zou ; Zhongyan, Meng
Author_Institution :
Dept. of Electron. Eng., Xi´´an Jiaotong Univ., China
Abstract :
A method of preparation of ZnO varistors, presynthetic spinels, was explored and its influence on electrical properties was examined. Microstructural features and distribution characteristics of the spinel phase in ZnO varistors were also investigated by electron probe microanalysis and TEM (transmission electron microscopy). The electrical properties of two types of samples are compared and discussed in relation to the spinel characteristics. The procedure of presynthetic spinels results in a drop of breakdown voltage of about 50%, a one-order decrease of leakage current, and a significant improvement of thermal stability. The I-V characteristics of ZnO varistors are influenced not only by the Bi2O3 intergranular phase, but also by the distribution characteristics of the spinel phases, which can be modified considerably by varying the technological procedure
Keywords :
II-VI semiconductors; ceramics; electric breakdown of solids; electron probe analysis; grain boundaries; grain growth; leakage currents; semiconductor technology; transmission electron microscope examination of materials; varistors; zinc compounds; Bi2O3 intergranular phase; I-V characteristics; TEM; ZnO varistors; breakdown voltage; distribution characteristics; electrical properties; electron probe microanalysis; leakage current; preparation; presynthetic spinels; semiconductors; spinel phase; thermal stability; transmission electron microscopy; Ball milling; Cooling; Diffraction; Electrons; Furnaces; Leakage current; Low voltage; Microstructure; Varistors; Zinc oxide;
Conference_Titel :
Electronic Components and Technology Conference, 1992. Proceedings., 42nd
Conference_Location :
San Diego, CA
Print_ISBN :
0-7803-0167-6
DOI :
10.1109/ECTC.1992.204225
