作　　者： ; ; ; ;

机构地区： 华南理工大学

出　　处： 《华南理工大学学报（自然科学版）》 2009年第3期43-46,共4页

摘　　要： 用溶胶-凝胶法制备了La0.8Sr0.2Mn0.86Fe0.14-xCoxO3（x=0.01,0.02,0.03）粉晶,用XRD表征了其晶体结构,用微波网络矢量分析仪测量了样品在2-18GHz频率范围内的复介电常数和复磁导率,根据测量数据得到了微波反射率与频率的关系曲线.结果表明：La0.8Sr0.2Mn0.86Fe0.13Co0.01O3厚度为1.80mm时,吸收峰高27.9 dB,2-18GHz吸收带宽5.3GHz;厚度为2.00mm时,吸收峰高26 dB,2-18GHz吸收带宽4.9GHz.从电、磁损耗角正切看,样品既有介电损耗又有磁损耗,但介电损耗要大于磁损耗.同时掺杂Fe、Co改变了Mn^3＋O Mn^4＋体系的输运性质,改变材料的电磁参数可改善材料的微波吸收性能. La0.8Sr0.2Mn0.86Fe0.14-xCoxO3（ X = O. 01, 0. 02, 0. 03 ） crystal powders were synthesized via the sol-gel method, and the crystal structure of the product was characterized by means of XRD. Then, the complex permittivity and permeability of the product in the frequency range of 2 - 18 GHz were measured using a microwave vector network analyzer. Moreover, the curves describing the relationship between the microwave reflectivity and the frequency were obtained according to the measured data. The results show that, with a thickness of 1.80 mm, La0.8Sr0.2Mn0.86Fe0.13Co0.01O3 is of an absorption peak height of 27. 9 dB and an absorption bandwidth in 2 -18 GHz of 5.3 GHz, while with a thickness of 2.00mm, the height decreases to 26dB and the bandwidth to 4. 9GHz. According to the tangents of both electric loss and magnetic loss angles, the microwave absorption attributes to both the dielectric and the magnetic loss, especially the former. It is also indicated that the doping of Fe and Co changes the double-exchange of Mn^3＋--O--Mn^4＋ system and the electromagnetic parameters of the material, thus improving the microwave-absorbing properties.

关 键 词： 吸波材料 掺杂 复介电常数 复磁导率

领　　域： [电气工程] [一般工业技术] [理学] [理学]