摘要
以硝酸镧、氯化亚锡和聚乙烯吡咯烷酮(PVP)为原料,采用电喷法结合后续高温煅烧技术制备了La^3+掺杂Sn O2中空微纳米球。通过热重分析仪、Fourier变换红外光谱仪、X射线衍射仪、扫描电子显微镜和矢量网络分析仪等手段对目标产物进行了表征,研究了Sn O2微纳米球中空结构的形成机制及La^3+掺杂对其物相、微观形貌和吸波性能的影响。研究表明:La^3+掺杂Sn Cl2/PVP前驱体聚合物呈完整球形,表面光滑,球径分布在0.5~2.2μm之间。经600℃煅烧后,均生成了单一金红石型Sn O2,且La^3+的加入未改变Sn O2的晶体结构;煅烧后产物均为中空球状,球面由许多小颗粒堆积而成,表面粗糙不平。当匹配厚度为2 mm时,La^3+掺杂比例为0.6%(摩尔分数)的产物的吸波效果最佳:最低反射率为–29 d B,对应的吸收频率为11.1 GHz,低于–10 d B的吸收频带为10.0~13.0 GHz;该掺杂比例的产物随匹配厚度增加,最低反射率向低频移动,在8 GHz以下的最佳匹配厚度为4 mm,在此厚度下吸波性能优良:最低反射率为–27 d B,对应的吸收频率为4.9 GHz,低于–10 d B的吸收频带为4.5~5.8 GHz。
La^3+-doped Sn O2 hollow micro/nanospheres were prepared by electrospray and calcination techniques with lanthanum nitrate,stannous chloride and polyvinylpyrrolidone(PVP)as raw materials.The formation mechanism of hollow structure was analyzed.The crystalline phase and micromorphology of the samples were examined by thermal gravimetric analysis(TGA),Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD)and field emission scanning electron microscopy(FESEM).The microwave absorption properties of La^3+-doped Sn O2 were determined by a vector network analyzer.The results show that La^3+-doped Sn Cl2/PVP precursor polymer appears smooth spheres with the diameters of 0.5–2.2μm.The pure rutile structure of Sn O2 forms at 600℃,and La^3+doping does not change the crystal structure.La^3+-doped Sn O2 micro/nanospheres appear to be a hollow structure,and the surfaces are made up of massive small particles.The optimum microwave absorption properties of La^3+-doped Sn O2 hollow micro/nanospheres with the matching thickness of 2 mm can be obtained when the doping ratio of La^3+is 0.6%(in mole).The minimum reflectivity can reach–29 d B at 11.1 GHz,and the frequency band with a reflectivity less than–10 d B is 10.0–13.0 GHz.When the doping ratio of La^3+is 0.6%,the minimum reflectivity of La^3+-doped Sn O2 hollow micro/nanospheres shifts to a low frequency as the matching thickness increases.The matching thickness is 4 mm at lower than8 GHz,thus obtaining the optimum microwave absorption properties.The minimum reflectivity can reach–27 d B at 4.9 GHz,and the frequency band with a reflectivity less than–10 d B is 4.5–5.8 GHz.
作者
赵芳
张飒
唐香珺
程兆刚
韩凯
ZHAO Fang;ZHANG Sa;TANG Xiangjun;CHENG Zhaogang;HAN Kai(Shijiazhuang Campus of Army Engineering University,Shijiazhuang 050003,China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2020年第1期1-7,共7页
Journal of The Chinese Ceramic Society
基金
河北省自然科学基金青年科学基金(E2015506011)
陆军工程大学石家庄校区科研创新发展基金(KYSZJQZL1910)。
关键词
镧掺杂
二氧化锡
电喷法
中空微纳米球
微波吸收性能
lanthanum doping
stannic oxide
electrospray
hollow micro/nanospheres
microwave absorption property
