| 摘要: |
| 电磁屏蔽是有效抑制电磁危害的手段之一，电磁屏蔽材料的性质与其抗电磁辐射能力密切相关。CrxTey合金材料的晶体结构呈现二维多层结构，具有优异的屏蔽电磁波的潜能，可以作为未来航天领域的优选材料。通过脉冲激光沉积手段，CrTe2和Cr4Te5两种组分薄膜被外延沉积在蓝宝石Al2O3衬底上。X射线衍射和原子力显微镜测量结果显示薄膜为外延单晶生长，同时薄膜表面的粗糙度起伏不超过2 nm。其中光电子能谱对Cr4Te5薄膜的扫描结果证明其化学计量比符合4∶5，且在空气中放置一个月后未发现明显氧化。变温的磁化强度测量显示CrTe2和Cr4Te5薄膜分别在198 K和257 K发生标准的顺磁--铁磁相变行为。温度范围从5 K到320 K，薄膜始终显示为金属性。电输运物理机理的模拟分析得出，电子--电子散射和电子--磁子散射分别对居里点以上和以下导电性起主导作用。这些优异的性能集一体，使得CrxTey材料在未来航天领域可以发挥电磁屏蔽的重要作用。 |
| 关键词: 二维材料 电磁屏蔽 磁性薄膜 金属导电 |
| DOI： |
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| 基金项目:国家自然科学基金（11974181）；鸿鹊创新中心开放基金（HQ202102003） |
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| High Efficiency Electromagnetic Shielding and the Aerospace Applications of Two Dimensional Layered CrxTey Ultrathin Film |
| ZHANG Ruiju,YU Benwei,HU Dazhi,FAN Jiyu |
| (1. Nanjing Ecological Environment Monitoring and Control Center, Nuclear and Radiation Office，Nanjing 210000, China;2. Department of Applied Physics, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China) |
| Abstract: |
| Electromagnetic shielding is one of the effective means to restrain electromagnetic hazards, and the properties of electromagnetic shielding materials are strongly correlated with their ability to resist electromagnetic radiation. The CrxTey material shows a two-dimensional crystal structure，which will be possibly utilized in the future electromagnetic shielding area of aerospace due to their excellent potentials for shielding electromagnetic waves. By using pulsed laser deposition technology, we realized a single crystal growth of CrTe2 and Cr4Te5 thin films on Al2O3 substrate. Their epitaxial growth characteristics and the surface roughness have been examined by the measurement of X-ray diffraction and the atomic force microscopy. The results of X-ray diffraction show that all of thin films epitaxially grow. Meanwhile, their surface roughness is also no more than 2 nm. For the Cr4Te5 thin film, the detection of X-ray photoelectron spectra proves that its chemical components' ratio is consistent with 4∶5. Its chemical property can remain very stable as it is placed at atmospheric environment for one month. Based on the measurement of magnetiza-tion dependence on temperature, we find thatan obvious paramagnetic-ferromagnetic phase transition occurs at 198 K and 257 K, respectively for CrTe2 and Cr4Te5 films. We also proved that the film conductivity exhibited a metallic electronic transport at the temperature range of 5~320 K by the measurement of resistance dependence on temperature. The study of electrical conductivity mechanism shows that electron-electron scattering and electron-magnet on scattering respectively play an important role in conductivity above and below the Curie point. Based on these unique properties, we believe that CrxTey will play a key role in the ongoing development of aerospace field for the electromagnetic shielding. |
| Key words: Two dimensional Electromagnetic shielding Magnetic film Metallic conductivity |