Effect of temperature on dielectric response in X-band of silicon nitride ceramics prepared by gelcasting
Due to the drastic aerodynamic heating effect in supersonic aircrafts, the operational performance of wave-transmitting dielectric ceramics functionalized radomes strongly depends on the temperature and oxidation. In this paper, the evolution of microwave dielectric responses in Si3N4 ceramics via g...
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doaj-78aa54a9accb4f4dbe52bdf74e50c5222020-11-25T02:26:03ZengAIP Publishing LLCAIP Advances2158-32262018-07-0187075127075127-610.1063/1.5033965095807ADVEffect of temperature on dielectric response in X-band of silicon nitride ceramics prepared by gelcastingShiyu Shao0Heng Luo1Lianwen Deng2Jun He3Shengxiang Huang4School of Minerals Processing and Bioengineering, School of Physics and Electronics, Central South University, Changsha 410083, ChinaSchool of Minerals Processing and Bioengineering, School of Physics and Electronics, Central South University, Changsha 410083, ChinaSchool of Minerals Processing and Bioengineering, School of Physics and Electronics, Central South University, Changsha 410083, ChinaSchool of Minerals Processing and Bioengineering, School of Physics and Electronics, Central South University, Changsha 410083, ChinaSchool of Minerals Processing and Bioengineering, School of Physics and Electronics, Central South University, Changsha 410083, ChinaDue to the drastic aerodynamic heating effect in supersonic aircrafts, the operational performance of wave-transmitting dielectric ceramics functionalized radomes strongly depends on the temperature and oxidation. In this paper, the evolution of microwave dielectric responses in Si3N4 ceramics via gelcasting over a wide temperature range (25°C∼800°C) is investigated experimentally and theoretically. Specifically, the relative increment rate of real permittivity over evaluated temperature range is 4.46% at 8.2GHz and 8.67% at 12.4GHz, while the imaginary permittivity remains less than 0.06. Taking temperature-dependent polarized bound charge and damping coefficient into consideration, a revised dielectric relaxation model with Lorentz correction for Si3N4 ceramics has been established, which agrees well with evolution of experimental results. Furthermore, the best fitting results indicate that the activation energy of electrons Ea (15.46 ∼17.49 KJ/mol) is less than that of lattice Eb (33.29∼40.40 KJ/mol), which could be ascribed to the binding force between the electrons and nucleus is lower than covalent bonding force of lattice. Besides, excellent restorable feature of permittivity after heat-treatment lays a solid foundation for radome materials serviced in high temperature circumstances.http://dx.doi.org/10.1063/1.5033965 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Shiyu Shao Heng Luo Lianwen Deng Jun He Shengxiang Huang |
spellingShingle |
Shiyu Shao Heng Luo Lianwen Deng Jun He Shengxiang Huang Effect of temperature on dielectric response in X-band of silicon nitride ceramics prepared by gelcasting AIP Advances |
author_facet |
Shiyu Shao Heng Luo Lianwen Deng Jun He Shengxiang Huang |
author_sort |
Shiyu Shao |
title |
Effect of temperature on dielectric response in X-band of silicon nitride ceramics prepared by gelcasting |
title_short |
Effect of temperature on dielectric response in X-band of silicon nitride ceramics prepared by gelcasting |
title_full |
Effect of temperature on dielectric response in X-band of silicon nitride ceramics prepared by gelcasting |
title_fullStr |
Effect of temperature on dielectric response in X-band of silicon nitride ceramics prepared by gelcasting |
title_full_unstemmed |
Effect of temperature on dielectric response in X-band of silicon nitride ceramics prepared by gelcasting |
title_sort |
effect of temperature on dielectric response in x-band of silicon nitride ceramics prepared by gelcasting |
publisher |
AIP Publishing LLC |
series |
AIP Advances |
issn |
2158-3226 |
publishDate |
2018-07-01 |
description |
Due to the drastic aerodynamic heating effect in supersonic aircrafts, the operational performance of wave-transmitting dielectric ceramics functionalized radomes strongly depends on the temperature and oxidation. In this paper, the evolution of microwave dielectric responses in Si3N4 ceramics via gelcasting over a wide temperature range (25°C∼800°C) is investigated experimentally and theoretically. Specifically, the relative increment rate of real permittivity over evaluated temperature range is 4.46% at 8.2GHz and 8.67% at 12.4GHz, while the imaginary permittivity remains less than 0.06. Taking temperature-dependent polarized bound charge and damping coefficient into consideration, a revised dielectric relaxation model with Lorentz correction for Si3N4 ceramics has been established, which agrees well with evolution of experimental results. Furthermore, the best fitting results indicate that the activation energy of electrons Ea (15.46 ∼17.49 KJ/mol) is less than that of lattice Eb (33.29∼40.40 KJ/mol), which could be ascribed to the binding force between the electrons and nucleus is lower than covalent bonding force of lattice. Besides, excellent restorable feature of permittivity after heat-treatment lays a solid foundation for radome materials serviced in high temperature circumstances. |
url |
http://dx.doi.org/10.1063/1.5033965 |
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