水热合成β-MnO_2纳米棒的电磁特性

ELECTROMAGNETIC PROPERTIES OF β-MANGANESE DIOXIDE NANORODS BY HYDROTHERMAL SYNTHESIS

采用水热合成法,以(NH4)2S2O8作氧化剂,以MnSO4·H2O为锰源,制备了β-MnO2纳米棒。利用X射线粉末衍射、扫描电子显微镜、透射电子显微镜、振动样品磁强计和热重分析对产物进行成分、晶型、形貌、磁性能和热稳定性分析,并通过电磁参数的测试对产物的电磁特性以及电磁波损耗机制进行阐述。结果表明:所制得粉体是直径约为100nm的β-MnO2纳米棒,其复介电常数实部为17.39～12.06,虚部为3.70～7.23;复磁导率实部和虚部都很小,分别为0.95～1.05和0～0.20。最后分析了β-MnO2纳米棒的电磁波损耗机制。

β-MnO2 nanorods were successfully prepared by hydrothermal synthesis, using （NH4）2S2O8 as the oxidizing agent and the Mn element came from MnSO4-H2O. The components, crystal structure, morphology, magnetic characteristic and thermal stability of the products were characterized by powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy（SEM）, vibrating sample magnetometry and thermogravimetric analysis, respectively. In addition, the electromagnetic properties and microwave loss mechanism of β-MnO2 nanorods were described according to tested electromagnetic parameters, such as the dielectric constant and permeability. The results show that the diameter of β-MnO2 nanorods is about 100 nm, and the real and the imaginary parts of complex relative permittivity are about 17.39-12.06 and 3.70-7.23, respectively, and the real and imaginary part of complex permeability are very small： about 0.95-1.05 and 0-0.20, respectively. Finally, the microwave loss mechanism of β-MnO2 nanorods is suggested.