Characteristics of permittivity and permeability spectra in range of 2-18 GHz microwave frequency for La1-xSrxMn1-yByO3(B=Fe,Co,Ni)
Doped LaMnO3 has unusual electromagnetic properties,which makes it possible for this material to be used for absorbing microwave.LaMnO3 systems doped by Sr at site A and Fe or Co,Ni at site B were prepared by sol-gel as an microwave absorption material and their permittivity and permeability spectra were measured by microwave vector network analyzer in the frequency range of 2.18 GHz.A novel phenomenon is discovered that the complex permittivity,complex permeability and electromagnetic loss tangent have suddenly a step change at a certain frequency and the step-change frequency is relevant to content of Sr and Fe or Co,Ni.The samples show mainly dielectric loss when microwave frequency is smaller than the step-change frequency,and mainly magnetic loss when larger than that frequency.It is indicated that anti-ferromagnetic clusters in the material can absorb energy quantum of microwave electromagnetic field to change into ferromagnetic clusters because they can overcome higher energy barrier when the frequency of incident microwave reaches a certain value.
microwave absorption material complex permittivity complex permeability rare-earth Mn oxide doped LaMnO3
ZHOU Ke-sheng WANG Da HUANG Ke-long YIN Li-song ZHOU Yi-ping GAO Song-hua
School of Physics Science and Technology,Central South University,Changsha 410083,China School of Physics Science and Technology,Central South University,Changsha 410083,China;School of Ph School of Chemistry and Chemical Engineering,Central South University,Changsha 410083,China
国际会议
2007年国际有色金属大会(International Conference of Nonfereous Materials 2007)(ICNFM)
长沙
英文
2007-11-28（万方平台首次上网日期，不代表论文的发表时间）