摘要
在微波段具有高复合磁导率的磁性金属薄膜,近年来是微波吸收材料的研究热点。但由于其金属性太强,微波信号极易被薄膜表面反射。该文采用高电阻率的W型六角铁氧体BaZnCoFe_(15.5)O_(27)粉末原料,使用等离子喷涂制备出平整致密的铁氧体薄膜。振动样品磁强计(VSM)测试结果表明,所制备样品是典型的软磁薄膜。矢量网络分析仪微带线法证明,增大铁氧体吸收剂的宽厚比(即颗粒的面内尺寸与其厚度之比)可提高其自身的二维形状各向异性,有效提升吸收剂的微波磁损耗性能。在2 GHz处,薄膜的磁损耗和磁损耗角显著高于粉末。微磁学仿真表明,高度弥散的磁化分布所产生的非一致进动,有助于拓宽薄膜的微波吸收带宽,值得进一步优化制备工艺以深入研究其微波吸收机制。
Magnetic metal films with high complex permeability,have become a research hotspot in microwave absorption materials recently.Unfortunately,the incident microwave is easily reflected on the surface of metal film.Therefore,this work is aimed to deposit flat and dense ferrite film on glass substrate by plasma spraying technique,using high resistivity W-shaped hexagon ferrite BaZnCoFe_(15.5)O_(27) raw powder.Vibrating sample magnetometer(VSM)test results prove that the prepared films are typical soft magnetic films.The test results of SEM(scanning electron microscope)and microstrip line method with vector network analyzer confirm,the improving aspect ratio(the ratio of width to thickness)of ferrite particle can further raise its two-dimensional shape anisotropy,which can effectively improve the microwave magnetic loss performance of ferrite film absorber.It is certified that,the prepared sample's imaginary permeability and magnetic loss angle at 2 GHz is significantly greater than ferrite powder.Micromagnetic simulation results show that the non-uniform magnetization precession,caused by the highly-diffused magnetization distribution,can help widen the microwave absorption bandwidth of ferrite absorber.So it is of great value to further optimize the ferrite films’preparing technology and promote in-depth research of its microwave absorption mechanism.
基金
江苏省自然科学基金(BK20210436)。
关键词
铁氧体薄膜
等离子喷涂技术
宽厚比
磁损耗
磁损耗角
微磁学仿真
ferrite film
plasma spraying technique
aspect ratio
imaginary permeability
magnetic loss angle
micromagnetic simulation
