溶胶-凝胶法制备La_(1-x)Sr_(x)MnO_(3)及其电磁性能研究  

Electromagnetic Properties of La_(1-x)Sr_(x)MnO_(3) Prepared by Sol-Gel Method

作　　者：王伟超 刘顾 汪刘应 葛超群 王龙 许可俊 陈孟州 Wang Weichao;Liu Gu;Wang Liuying;Ge Chaoqun;Wang Long;Xu Kejun;Chen Mengzhou(Rocket Force University of Engineering,Xi’an 710025,China)

机构地区：[1]火箭军工程大学,陕西西安710025

出　　处：《稀有金属材料与工程》2022年第3期1003-1010,共8页Rare Metal Materials and Engineering

基　　金：国防科技基础加强计划技术领域基金(2020-JCJQ-JJ222);陕西省“特支计划”(陕组通字(2020)44号)。

摘　　要：采用溶胶-凝胶法制备了La_(1-x)Sr_(x)MnO_(3)(LSMO)(x=0,0.1,0.2,0.3)纳米微粉。探究了 Sr^(2+)的掺杂量对LSMO晶体结构、磁学性质、电磁特性和微波吸收性能的影响。结果表明,随 Sr^(2+)含量的升高,样品的晶格常数和Mn-O-Mn键角增大,平均晶粒尺寸逐渐下降,样品出现从反铁磁性向铁磁性的转变,复介电常数呈先增大后减小的趋势。在有效的波频段为2~18 GHz内,x=0的样品在厚度为2 mm时有最佳吸波效果,反射率损耗小于–10 dB对应的有效吸波频段为12.5~18 GHz,有效带宽达到5.5 GHz;Sr^(2+)的掺杂可使吸波频段有效向低频移动,在X波段内,x=0.2的样品在厚度为2.3 mm时的有效带宽达2.6 GHz,证明LSMO是一种性能优异的介电损耗型吸波材料。La_(1-x)Sr_(x)MnO_(3)(x=0,0.1,0.2,0.3)nanometer powders were prepared by sol-gel method.The crystal structure,magnetic properties,electromagnetic properties and microwave absorption properties of LSMO with different doping amounts of Sr_(2+)were investigated.The results show that with the increase of the amount of Sr^(2+),the lattice constant and Mn-O-Mn bond angle increase,while the average grain size decreases gradually and the complex dielectric constant increases first and then decreases.The LSMO changes from antiferromagnetism to ferromagnetism when Sr^(2+)is doped.In the range of 2~18 GHz,the best absorbing properties can be arrived when the doping amount of Sr^(2+)is 0 and the thickness is 2 mm.The effective frequency band corresponding to the reflectivity less than–10 dB is 12.5~18 GHz and the effective bandwidth reaches 5.5 GHz.The doping of Sr^(2+)can make the absorbing bandwidth move to the low frequency availably.In the X-band,the effective bandwidth of the LSMO reaches 2.6 GHz when the doping amount of Sr^(2+)is 0.2 and the thickness is 2.3 mm.It is proved that LSMO is a kind of dielectric loss absorbing material with excellent performance.

关 键 词：钙钛矿 La_(1-x)Sr_(x)MnO_(3) 电磁性能 吸波性能 溶胶-凝胶法 

分 类 号：TB34[一般工业技术—材料科学与工程]