【作者】 赵伟；

【导师】 吴起白；

【作者基本信息】 广东工业大学 ， 微电子学与固体电子学， 2011， 硕士

【摘要】 随着人类物质文化生活水平的不断提高,电子信息科学技术的发展,电子设备在人类生活环境中的应用越来越广泛,正因如此电磁波污染也相应变得日益严重,直接威胁到人类的健康,如何解决电磁波的污染成为了改善环境的又一新课题。另外随着军事领域和信息安全领域技术的飞速发展,微波吸收材料军事领域的应用受到亲睐,其研究日益受到各国重视。特别是氧化锌材料吸波性能特性较好、制备工艺简单,获得诸多学者的广泛关注与研究。本论文通过在乙酸锌溶液中添加锰、镍、钴、锰+镍以及锰+钴等过渡金属的乙酸盐,并结合利用水浴法制备亚微米级的棒状掺杂氧化锌粉末。采用X-射线衍射仪、能谱仪、扫描电子显微镜对氧化锌样品的结构、成分及形貌进行表征分析。利用振动样品磁强计和矢量网络分析仪测试其静态磁性及电磁特性,同时对样品的微波反射率进行模拟,详细研究掺杂过渡金属对氧化锌的微波吸收性能的影响。实验结果表明利用掺杂氧化锌作为吸收剂,环氧树脂为基体制备的微波吸收复合材料是一种很好的微波吸收材料。主要结果如下：(1)锰、镍、钻、二元(锰+镍,锰+钴)等掺杂对氧化锌样品的形貌影响不大,少量的掺杂不会改变氧化锌的晶体结构。(2)静态磁性分析发现掺杂氧化锌样品磁性微弱,说明掺杂不能增加氧化锌磁损耗这一吸波机制。(3)电磁参数的测试结果显示掺杂可以有效的改善氧化锌的介电性质。(4)根据样品的介电常数进行模拟,结果发现,过渡金属掺杂能够显著地改善氧化锌样品的微波吸收性能,掺杂元素种类及浓度均能够对氧化锌样品的微波吸收性能产生明显影响。掺锰、镍和钴的氧化锌其最大微波吸收峰值分别可以达到80dB、72.5dB和65.4dB；吸收频率分别位于9.9GHz、11.6GHz和10GHz；分别在相对中频、高频和低频区域表现出较大的吸收能力。研究还发现,吸波效果随着掺杂浓度变化存在最佳值,高于或者低于该掺杂浓度时吸波效果会相对较差。更多还原

【Abstract】 Nowadays, with the development of electronic industry, people’s living standards keep enhancing, and various electronic devices are emerging. Subsequently electromagnetic wave pollution is also increasing day by day, greatly threatening people’s health. Besides, along with military and information security technology’s fast development, applications of microwave absorbing material has become more and more, therefore, and research of such materials is gaining more and more attention. ZnO receives much extensive research due to its good characteristic and easy fabrication.In this paper, transition metals are doped into the zinc oxide by the decomposition of acetate solid solutions, to fabricate doped zinc oxide with sub-micron rod structure, for investigating the doped material’s application perspective in microwave absorption. Five sub-micron rod structure materials are made through water-bath method: Mn, Ni, Co, Mn/Ni and Mn/Co doped ZnO. XRD, EDS, SEM are used to analyze their constitution and profile, and VSM is used to test its static magnetism, and vector network analyzer for electromagnetic characteristics using co-axial method. Relations between electromagnetic characteristics and doping concentrations are analyzed and compared. The obtained characteristics are applied to simulate the microwave reflectivity with material respectively. Relations between reflectivities of doped ZnO are also analyzed.The results indicate that microwave absorbing composite which uses doped zinc oxide as absorbent and uses paraffin as base shows an excellent performance in microwave absorbing. Main results of experiment are as follow:(1) Mn, Ni, Co, Mn/Ni, Mn/Co doped ZnO does not have difference morphology to normal ZnO. A small amount of doping will not change the crystal structure of ZnO. (2) Static magnetism analysis of doped ZnO shows very weak magnetism, which means doping does not bring in magnetic loss as a microwave absorbing mechanism. (3) The results of electromagnetic parameters test show that doping can effectively improve the dielectric properties of zinc oxide. (4) Simulation results based on sample’s permittivity show that transition matel doping can effectively improve the microwave absorbing of ZnO. Elements and concentration of doping both have important influence of ZnO’s microwave absorbing properties. The max absorbing peak of Mn doped, Ni doped and Co doped ZnO reaches 80 dB(f=9.9 GHz),72.5 dB(f=11.6 GHz) and 65.4 dB(f=10 GHz) respectively. They act in relatively low, medium and high frequency zone respectively. It was found that the absorption reaches peak value at certain concentration, and higher or lower concentration does not yield better results.更多还原