| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 7994554 | Journal of Alloys and Compounds | 2018 | 22 Pages |
Abstract
The dielectric properties of SiC ceramics were investigated in the temperature range from room temperature to 873Â K and frequency range from 102 to 106Â Hz. Giant dielectric behavior was observed in SiC ceramics in the temperature range above 600Â K. This behavior strongly depends on sample thickness. Our results revealed that the surface of the sintered SiC sample was covered by a SiO2 layer. Oxygen vacancies in the surface layer diffuse into the inner part giving rise to two thermally activated dielectric relaxations. The low-temperature relaxation was argued to be a polaron relaxation caused by the hopping motions of oxygen vacancies, whereas the high-temperature one is a Maxwell-Wagner relaxation mainly caused by the surface layer.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
J. Zhang, D.Y. Xu, L. Tong, H.C. Qi, D.L. Zhang, C.C. Wang,