Modeling for high-temperature dielectric behavior of multilayer Cf/Si3N4 composites in X-band |
| |
| Affiliation: | 1. Innovation Research Team for Advanced Ceramics, Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China;2. State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China;3. Ceramic Materials Engineering, University of Bayreuth, Bayreuth 95447, Germany;4. State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620, China;5. Research Institute of Functional Materials, Donghua University, Shanghai 201620, China;1. Department of Aerospace Engineering, KAIST, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701, Republic of Korea;2. Agency for Defense Development (ADD), Daejeon 305-152, Republic of Korea;1. Department of Chemical and Materials Engineering, Ming Hsin University of Science and Technology, Hsinfeng, Hsinchu 304, Taiwan, ROC;2. Chemical Systems Research Division, Chung-Shan Institute of Science & Technology, Taoyuan 325, Taiwan, ROC;1. Science and Technology on Thermostructural Composite Materials Laboratory, Northwestern Polytechnical University, 710072 Xi''an, China;2. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, 710072 Xi''an, China |
| |
| Abstract: | The high-temperature dielectric behavior of multilayer Cf/Si3N4 composites fabricated by gelcasting and pressuureless sintering was intensively investigated at temperatures coverage up to 800 °C in X-band (8.2–12.4 GHz). Experimental results have shown the permittivity of Si3N4 matrix exhibits excellent thermo-stability with temperature coefficient lower than 10−3 °C−1. Besides, both the real and imaginary parts of permittivity of multilayer Cf/Si3N4 composites exhibit positive temperature coefficient characteristic which attributed to the enhancement of space charge polarization. Furthermore, temperature-dependent permittivity of Cf/Si3N4 composites is demonstrated to be well distributed on circular arcs with centers actually keep around the real () axis in Cole-Cole plane. Finally, the relaxation time for multilayer Cf/Si3N4 composites gradually increases from 216.1 ps to 250.2 ps when heated from room temperature to 800 °C, and is almost twice as much as a single cycle for electromagnetic wave in X-band which leads to continuous decrease in permittivity with frequency. |
| |
| Keywords: | High-temperature dielectric Relaxation time |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
