钙钛矿型锰氧化物La_(0.8)Sr_(0.2)MnO_3的高频性能  

Electromagnetic Properties of the Perovskite La_(0.8)Sr_(0.2)MnO_3 Manganese Oxide at High Frequency

作　　者：燕克兰[1] 王士娇 陈月光 范润华[1] 史志成[1] 张子栋[1] 魏玉磊[1] 

机构地区：[1]山东大学 材料液固结构演变与加工教育部重点实验室,山东济南250061 [2]山东同方鲁颖电子有限公司,山东临沂276300

出　　处：《稀有金属材料与工程》2013年第S1期186-188,共3页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51172131)

摘　　要：采用溶胶-凝胶法制得La0.8Sr0.2MnO3氧化物多晶样品。通过XRD、SEM对样品的微观结构进行了分析,结果表明:所得样品为钙钛矿结构,样品的颗粒大小比较均匀,平均粒度约100nm。利用阻抗分析仪对样品的介电常数和磁导率的频谱(10MHz～1GHz和1MHz～1GHz)进行了研究。研究表明,在整个测试频率范围内,La0.8Sr0.2MnO3的介电常数实部和虚部随频率的升高而降低。La0.8Sr0.2MnO3的复磁导率的频谱谱线为典型的弛豫型谱线,磁导率实部在1MHz时为6.2,共振频率fr为50MHz,共振时虚部峰值为2.8;磁谱测试表明材料的弛豫损耗峰出现在频率f≤300MHz的频率范围内,在此频率区域引起损耗的机制主要是畴壁共振。The polycrystalline La0.8Sr0.2MnO3 oxide was prepared by a sol-gel method. The microstructure of the samples was observed by means of XRD and SEM. The results show that La0.8Sr0.2MnO3 oxide presents perovskite structure, and the particle size is well-distributed with the average size of about 100 nm. The permittivity and permeability of the sample were measured in the frequency range from 10 MHz and 1 MHz to 1GHz by Impedance Analyzer. The value of real and imaginary permittivity decreases with increasing the frequency. The complex permeability spectrum curve of La0.8Sr0.2MnO3 oxide is typical of relaxation spectrum line. The real permeability is 6.2 at the frequency of 1 MHz, and the resonance frequency f r of the complex permeability is 50 MHz with the imaginary permeability peak value of 2.8. Magnetic spectrum shows that the relaxation loss peak appears in the frequency range of f≤300 MHz, and in this frequency area, the relaxation is attributed to the effect of domain wall resonance.

关 键 词：钙钛矿 溶胶-凝胶法 复介电常数 磁导率 弛豫型 

分 类 号：TB34[一般工业技术—材料科学与工程]