Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-02T23:22:38.800Z Has data issue: false hasContentIssue false
  • English
  • Français

Effect of process variables on the grain growth and microstructure of ZnO–Bi2O3 varistors and their nanosize ZnO precursors

Published online by Cambridge University Press:  03 March 2011

Sunita Hingorani ,
D.O. Shah  and
M.S. Multani
Sunita Hingorani
Affiliation:
Center for Surface Science and Engineering, University of Florida, Gainesville, Florida 32611
D.O. Shah
Affiliation:
Center for Surface Science and Engineering, University of Florida, Gainesville, Florida 32611
M.S. Multani
Affiliation:
Materials Research Group, Tata Institute of Fundamentals Research, Bombay 400 005, India
Get access

Abstract

The basic building block of the ZnO varistor is the ZnO grain formed as a result of sintering. Nanosized ZnO particles are prepared by carrying out the reaction in the controlled size nanoreactors—the droplets of microemulsions. Chemical doping of the ZnO nanoparticles provides ZnO-based ceramic varistors displaying superior varistor properties. These varistors show a higher value of the nonlinear coefficient, lower leakage current, and higher critical electric field value as compared to those for conventional samples in their log E versus log J curve. The present work has also been aimed at studying the effect of processing variables such as sintering temperature and duration on the microstructure and grain growth of ZnO nanoparticles and ZnO-Bi2O3 ceramics. The activation energy calculated from this data is found to be 175 kJ/mol for pure ZnO. For Bi2O3-doped ZnO, the activation energy is found to decrease considerably (∼148 kJ/mol). All these advantages are due to greater structural homogeneity, smaller particle size, higher surface area, and higher density of the ZnO nanoparticles which are precursors for ZnO varistors, as compared to coarser particles for making varistors.

Type
Articles
Information
Journal of Materials Research , Volume 10 , Issue 2 , February 1995 , pp. 461 - 467
Copyright
Copyright © Materials Research Society 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1Gupta, T. K., J. Am. Ceram. Soc. 73 (7), 1817 (1990).CrossRefGoogle Scholar
2Asokan, T., Iyenger, G. N. K., and Nagabhushana, G. R., J. Am. Ceram. Soc. 70 (9), 643 (1987).CrossRefGoogle Scholar
3Burke, J. J., Leed, N. L., and Weiss, V., Ultrafine Grain-Ceramics (University Press, New York, 1970).CrossRefGoogle Scholar
4Henmngs, D. F. K., Hartung, R., and Reijnen, R. J. L., J. Am. Ceram. Soc. 73 (3), 645 (1990).CrossRefGoogle Scholar
5Rahaman, M. N., DeJonghe, L. C., Voigt, J. A., and Tuttle, B. A., J. Mater. Sci. 25, 737 (1990).CrossRefGoogle Scholar
6Snow, G. S., White, S. S., Cooper, R. A., and Armijo, J. R., Am. Ceram. Soc. Bull. 59, 617 (1980).Google Scholar
7Amiji, N., Tanno, Y., Okuma, H., and Kan, M., Adv. Ceram. Mater. 1 (3), 232 (1986).CrossRefGoogle Scholar
8Siegal, R. W., MRS Bull. 60 (1990).CrossRefGoogle Scholar
9Maher, G. H., Hutchins, C. E., and Ross, S. D., Am. Ceram. Soc. Bull. 72 (5), 73 (1993).Google Scholar
10Fletcher, P. D. I., Howe, A. M., Perrins, N. M., Robinson, B. H., Toprakcioglu, C., and Dore, D. C., Surfactants in Solution, edited by Mittal, K. L. and Lindman, B. (Plenum Press, New York, 1984), Vol. 3, p. 1745.Google Scholar
11Boutonnet, M., Kizling, J., Stenius, P., and Make, G., Colloids Surf. 5, 82 (209).Google Scholar
12Kon-no, K., Koide, M., and Kitahara, A., J. Chem. Soc. Jpn. 6, 815 (1984).Google Scholar
13Kandori, K., Shizuka, N., Kon-no, K., and Kitahara, A., J. Disp. Sci. Tech. 9, 61 (1988).CrossRefGoogle Scholar
14Hou, M. J. and Shah, D. O., J. Colloid. Interface Sci. 123, 398 (1988).CrossRefGoogle Scholar
15Pillai, V., Kumar, P., and Shah, D.O., J. Magn. Mag. Mater. 116, L299 (1992).CrossRefGoogle Scholar
16Kumar, P., Pillai, V., and Shah, D. O., Appl. Phys. Lett. 62, 675 (1993).Google Scholar
17Gupta, T. K. and Straub, W. D., J. Appl. Phys. 68, 851 (1990).CrossRefGoogle Scholar
18Chen, Y-C., Shen, C-Y., Chen, H-Z., Wei, Y-F., and Wu, L., J. Mater. Sci. 27, 1397 (1992).CrossRefGoogle Scholar
19Chen, Y-C., Shen, C-Y., Chen, H-Z., Wei, Y-F., and Wu, L., Jpn. J. Appl. Phys. 30 (1), 90 (1991).Google Scholar
20Nicholson, G. C., J. Am. Ceram. Soc. 48, 214 (1965).CrossRefGoogle Scholar
21Hingorani, S., Pillai, V., Kumar, P., Multani, M. S., and Shah, D. O., Mater. Res. Bull. XXVIII, 130 (1993).Google Scholar
22Dutta, S. K. and Spriggs, R. M., J. Am. Ceram. Soc. 53, 61 (1970).CrossRefGoogle Scholar
23Senda, T. and Bradt, R. C., J. Am. Ceram. Soc. 73, 106 (1990).CrossRefGoogle Scholar
24Hwang, J-H., Mason, T. O., and Dravid, V. P., J. Am. Ceram. Soc. 77, 1499 (1994).CrossRefGoogle Scholar
25Kirkpatrick, K. S., Mason, T. O., Balachandran, U., and Poeppel, R. B., J. Am. Ceram. Soc. 77, 1493 (1994).CrossRefGoogle Scholar
26Lauf, R. J. and Bond, W. D., Am. Ceram. Soc. Bull. 63, 279 (1984).Google Scholar
27Halle, S. M., Johnson, D. W., Wiseman, G. H., and Bowen, H. K., J. Am. Ceram. Soc. 72, 2004 (1989).CrossRefGoogle Scholar