【作者】 张佳； 段玉平； 荆慧； 刘顺华；

【Author】 ZHANG Jia,DUAN Yu-ping,JING Hui,LIU Shun-hua (School of Material and Engineering,Dalian University of Technology,Dalian 116085,China)

【机构】 大连理工大学材料科学与工程学院；

【摘要】 在外加3 T强磁场条件下成功制备出海胆球链状MnO₂粉末,并讨论了其形貌形成机制。利用X射线粉末衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）及矢量网络分析仪等对所得MnO₃粉末进行测试分析。结果表明,产物主要由α-MnO₂和γ-MnO₂两相组成。外加强磁场对制备的MnO₂粉末的电磁特性有很大影响。外加强磁场使复介电常数、电损耗正切值及复磁导率的实部减小,而复磁导率的虚部和磁损耗正切值则明显增大。并且,从根据传输线理论计算得到的反射损耗值曲线可以看出,外加强磁场后使反射损耗吸收峰变得更加平缓,且向高频方向移动。更多还原

【Abstract】 MnO₂ with a sea urchin-like ball chain shape has been synthesized in the extra high magnetic field （3T） via a simple hydrothermal route,and the formation mechanism for the grain shape was discussed.The synthesized samples were characterized by XRD,SEM,TEM and vector network analysis.Theα-MnO₂ andγ-MnO₂ are the major MnO₂ products.Throughout the whole frequency range,comparing to the sample synthesized without the high magnetic field,the dielectric constant,the electric loss tangent,and the real part of complex permeability for the sample synthesized in the high magnetic field are smaller.However,the imaginary part of complex permeability and the magnetic loss tangent value are larger.Furthermore,the theory calculated values of reflection loss shows that when the magnetic field is adopted,the absorption peak becomes smoother and shifts to higher frequency.更多还原