Study on ferro/anti-ferro exchange-coupled multilayer film for microwave magnetic devices

为了开发用于电感、滤波器、传输线等微波无源器件的新型高频磁性薄膜材料，引入了铁/反铁交换耦合。在这项研究中，Mn-Ir/Fe-Si交换耦合膜已被制备和表征。研究结果如下：1.一种利用铁/反铁交换耦合实现新型高频磁性材料的可能性众所周知，铁/反铁交换耦合在铁磁层中产生交换偏置磁场。本研究提出了一种利用铁/反铁交换耦合研制高频磁性材料的新思路. Mn-Ir/Fe-Si交换耦合薄膜的制备与表征（1）铁磁共振频率的控制研究发现，通过改变铁磁层厚度可以控制铁磁共振频率。例如，在Mn-Ir（10 nm）/Fe-Si薄膜中，FMR频率发生变化 ...更多信息 1.9从4.3 GHz的Fe-Si层厚度从10 nm改变为100。(2)Ru底层对Mn-Ir/Fe-Si薄膜磁性能的影响在底层Fe-Si中加入超薄Ru底层（1 nm），不仅可以提高薄膜的矫顽力，抑制磁各向异性色散，而且可以改善薄膜的表面粗糙度，从而使薄膜的FMR线宽变窄。通过引入Ru底层，可以制备出谐振损耗小的高频磁性材料。(3)一种宽带吸能磁性材料，不同Fe-Si层厚的Mn-Ir/Fe-Si多层膜具有多个FMR，适用于宽带噪声吸收材料。(4)为了研究Mn-Ir/Fe-Si薄膜的微波磁性能，基于Landau-Lifshitz-吉尔伯特方程，将Fe-Si交换刚度色散模型引入到微磁模拟中。据推测，这种交换刚度是由于Fe-Si晶粒取向和晶格缺陷。Fe-Si中交换刚度的色散导致自旋-自旋相互作用的损失，而交换偏置磁场的色散导致铁磁层厚时FMR线宽变宽。在铁/反铁交换耦合膜中引入较薄的铁磁层是开发窄线宽铁磁电阻材料的有效途径。(5)铁/反铁交换耦合薄膜在微波器件中的应用问题为了解决铁/反铁交换耦合薄膜在微波器件中的应用问题，研究了器件制备过程中热应力的影响。Mn-Ir/Fe-Si界面的交换能随温度的升高而单调下降，但在300℃时仍下降约30%。因此，可以认为器件工艺过程中性能的热退化并不严重.（1）铁/反铁交换耦合膜微波无源器件的研制新型铁/反铁交换耦合膜将应用于电感、滤波器、传输线器件等微波无源器件。(2)其他新型铁/反铁交换耦合薄膜的微波应用研究作为其他新型铁/反铁交换耦合薄膜材料，金属氧化物多层体系材料和金属氧化物纳米颗粒体系材料将被制备和表征。我们目前正在研究纳米颗粒铁/反铁交换耦合膜。少

In order to develop a new high frequency magnetic film material for various microwave passives such as inductor, filter and transmission-line device, a ferro/anti-ferro exchange-coupling been introduced. In this study, a Mn-Ir/Fe-Si exchange-coupled film has been fabricated and characterized. The results obtained are as follows.1. Apossibility of new high frequency magnetic material by means of ferro/anti-ferro exchange-couplingAs well-known, ferro/anti-ferro exchange coupling generates exchange bias magnetic field in the ferromagnetic layer. In this study, a new idea which high frequency magnetic material can be developed using ferro/anti-ferro exchange coupling has been proposed.2. Fabrication and characterization of Mn-Ir/Fe-Si exchange-coupled film(1) Control of ferromagnetic resonance frequency ; It was found that the ferromagnetic resonance (FMR) frequency can be controlled by changing ferromagnetic layer thickness. For example, in Mn-Ir(10nm)/Fe-Si film, the FMR frequency varies … More 1.9 from 4.3 GHz by changing Fe-Si layer thickness of 100 from 10nm.(2) Effect of Ru under-layer on the magnetic properties of Mn-Ir/Fe-Si film ; Ultra thin (1nm) Ru under-layer for bottom Fe-Si has a great effect of coercive force, suppression of magnetic anisotropy dispersion, and narrow FMR line width by improving surface roughness for the film. By introducing Ru under-layer, high frequency magnetic material with small resonance loss can be fabricated.(3) Wideband energy absorption magnetic material ; Mn-Ir/Fe-Si multilayer film with different Fe-Si layer thickness has plural FMRs and is suitable for wideband noise absorption material.(4) Analysis of microwave magnetic property ; In order to investigate microwave magnetic property of the Mn-Ir/Fe-Si film, exchange stiffness dispersion model for the Fe-Si has been introduced to the micromagnetic simulation based on the Landau-Lifshitz-Gilbert equation. It has been assumed such exchange stiffness is owing to the Fe-Si grain orientation and lattice defect. The exchange stiffness dispersion in Fe-Si gives rise to lose spin-spin interaction, and dispersion of exchange bias magnetic filed gives rise to wide FMR line width in case of thick ferromagnetic layer. In order to develop narrow FMR line width material, it is very effective to introduce thinner ferromagnetic layer to the ferro/anti-ferro exchange coupled film.(5) Problem in the application of ferro/anti-ferro exchange-coupled film to microwave devices ; In order to clarify the problem in the application of ferro/anti-ferro exchange-coupled film to microwave devices, influence of the thermal stress in the device fabrication process has been investigated. Although the exchange energy in Mn-Ir/Fe-Si interface decreases monotonously with increasing temperature, its decrease is about 30% even when 300℃. Hence it is considered that the thermal degradation of the property through the device process is not so serious.3. Future issues(1) Development of microwave passives using ferro/anti-ferro exchange-coupled film ; A new ferro/anti-ferro exchange-coupled film will be applied to the microwave passives such as inductor, filter and transmission-line device.(2) Investigation of other new ferro/anti-ferro exchange-coupled film for microwave application ; As other new ferro/anti-ferro exchange-coupled film material, metal-oxide multilayer system material and metal-oxide nano-granular system material will be fabricated and characterized. We currently investigate a nano-granular ferro/anti-ferro exchange coupled film. Less