Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-19T10:06:38.605Z Has data issue: false hasContentIssue false
  • English
  • Français

Grain boundary effects in NTC-PTC composite thermistor materials

Published online by Cambridge University Press:  26 July 2012

D. J. Wang ,
J. Qiu ,
Y. C. Guo ,
Z. L. Gui  and
L. T. Li
D. J. Wang
Affiliation:
State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
J. Qiu
Affiliation:
State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
Y. C. Guo
Affiliation:
State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
Z. L. Gui
Affiliation:
State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
L. T. Li
Affiliation:
State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
Get access

Extract

Yttrium-doped (Sr0.45Pb0.55)TiO3 ceramics have been studied by complex impedance analysis. As a sort of NTC-PTC composite thermistor, it exhibited a significantly large negative temperature coefficient of resistivity below Tc in addition to the ordinary PTC characteristics above Tc. It is found that the NTC effect in NTC-PTC materials was not originated from the deep energy level of donor (bulk behavior), but from the electrical behavior of the grain boundary. Therefore, the NTC-PTC composite effect was assumed to be a grain boundary effect, and yttrium was a donor at shallow energy level. The NTC-PTC ceramics were grain boundary controlled materials.

Type
Articles
Information
Journal of Materials Research , Volume 14 , Issue 1 , January 1999 , pp. 120 - 123
Copyright
Copyright © Materials Research Society 1999

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

1.Saburi, O., J. Am. Ceram. Soc. 44, 54 (1961).CrossRefGoogle Scholar
2.Kulwicki, B. M., in Advances in Ceramics, Vol. 1, Grain Boundary Phenomena in Electronic Ceramics, edited by Levinson, L. M. (The American Ceramic Society, Westerville, OH, 1981), p. 138.Google Scholar
3.Kuwabara, M., J. Am. Ceram. Soc. 73, 1438 (1993).CrossRefGoogle Scholar
4.Iijima, T., Okada, M., and Homma, M., ISIJ Int. 29, 229 (1989).CrossRefGoogle Scholar
5.Iwaya, S., Masumura, H., Taguchi, H., and Hamada, M., J. Electron. Ceram. Jpn. 19, 33 (1988).Google Scholar
6.Lee, C., Lin, I-N., and Hu, C-T., J. Am. Ceram. Soc. 77, 1340 (1994).CrossRefGoogle Scholar
7.Wang, D-J., Zeng, Z-Q., Gui, Z-L., and Li, L-T., Mater. Lett. 30, 275 (1997).CrossRefGoogle Scholar
8.Wang, D. J., Gui, Z. L., and Li, L.T., J. Mater. Sci.: Mater. in Electron. 8, 271 (1997).Google Scholar
9.Wang, D. J., Guo, Y. C., Gui, Z. L., and Li, L. T., Piezoelectrics & Acoustooptics 19, 268 (1997).Google Scholar
10.Wang, D. J., Guo, Y. C., Gui, Z. L., and Li, L. T., Piezoelectrics & Acoustooptics 19, 346 (1997).Google Scholar
11.Wang, D. J., Guo, Y. C., Gui, Z. L., and Li, L. T., Piezoelectrics & Acoustooptics 20, 103 (1998).Google Scholar
12.Wang, D. J., Ph.D. Dissertation, Tsinghua University, People's Republic of China (1997), p. 123.Google Scholar