复合材料结构设计与层间相互作用研究
发布时间：2019-07-06 09:17
【摘要】：近年来,研究发现复合结构磁性材料中存在着多种磁相互作用,材料的几何结构、磁性层的变化等均会引起材料内部相互作用机制的不同,进而影响材料的使用。另一方面,由于巨磁阻抗(GMI)效应在低场范围表现出极高的灵敏度,不仅可以在弱磁传感器等领域中得到应用,也被发展为复杂结构磁性材料的研究手段之一。为了进一步阐明复合结构丝内的相互作用,本文利用磁控溅射法在Cu丝衬底上制备了Ni_(80)Fe_(20)镀层,通过改变镀层厚度、层数,设计了具有不同几何结构的样品,重点考察了多磁性层复合结构丝内的磁偶极相互作用机制及其对材料GMI效应的影响。本文的主要工作包括以下几个方面:一、制备了Ni_(80)Fe_(20)/Cu单磁性层复合结构丝,系统地研究了镀层厚度对磁阻抗效应的影响。发现最大阻抗比随Ni_(80)Fe_(20)层厚度的增加呈现出先增大后减小的变化规律,与之对应的轴向偏置场呈先减小后增大的趋势,推测该现象与制备过程中产生的剩余压应力以及镀层表面形貌有关。Ni_(80)Fe_(20)层厚度为485nm时,复合结构丝的最大磁阻抗比最大,偏置场最小。由此可知,可以通过改变镀层厚度来控制镀层的磁性能。二、双磁性层Ni_(80)Fe_(20)(tout)/Ni_(80)Fe_(20)(tin)/Cu复合结构丝的制备和磁性能研究。通过改变样品内外磁性层的厚度,制备了具有内纵向外环向、双环向各向异性磁结构的复合结构丝。结果发现内纵向外环向样品的磁阻抗曲线呈双峰结构,与总厚度相同的单磁性层复合结构丝磁阻抗曲线几乎重合,说明这种情况下层间相互作用弱。双环向磁结构样品的磁阻抗曲线呈现出四峰结构,且内镀层的有效各向异性场Hk比同厚度的单磁性层样品的Hk大。这主要由于内外层磁结构相似时,层间相互作用强,从而引起了镀层各向异性场的变化。三、固定单层的溅射时间10分钟不变,多磁性层[Ni_(80)Fe_(20)]n/Cu复合结构丝的制备和磁性能研究。实验结果表明,随着镀层层数的增加,复合结构丝的最大磁阻抗比明显增大。n=1时,镀层具有纵向磁各向异性,这与镀层的剩余应力和表面形貌有关;而n=2,3,4时,镀层具有环向磁各向异性,层间的相互作用随层数的增加而增强,对磁阻抗曲线中Hp的抑制作用也增强。
[Abstract]:In recent years, it has been found that there are many kinds of magnetic interactions in the magnetic materials with composite structures. The geometric structure of the materials and the change of the magnetic layer will lead to the difference of the internal interaction mechanism of the materials, which will affect the use of the materials. On the other hand, because the giant magnetoimpedance (GMI) effect shows very high sensitivity in the low field range, it can not only be used in the field of weak magnetic sensors, but also developed into one of the research methods of magnetic materials with complex structures. In order to further elucidate the interaction in composite wire, Ni_ (80) Fe_ (20) coating was prepared on Cuwire substrate by magnetron splashing. By changing the thickness and number of layers, samples with different geometric structures were designed. The magnetic dipole interaction mechanism in multi-magnetic composite wire and its effect on GMI effect were investigated. The main work of this paper includes the following aspects: first, Ni_ (80) Fe_ (20) / Cu single magnetic layer composite structure wire was prepared, and the effect of coating thickness on magnetoimpedance effect was studied systematically. It is found that the maximum impedance ratio increases at first and then decreases with the increase of the thickness of Ni_ (80) Fe_ (20) layer, and the corresponding axial bias field decreases at first and then increases. It is inferred that this phenomenon is related to the residual compressive stress produced in the preparation process and the surface morphology of the coating. When the thickness of Ni _ (80) Fe_ (20) layer is 485nm, the maximum magnetoresistive ratio of the composite structural wire is the largest and the bias field is the smallest. Therefore, the magnetic properties of the coating can be controlled by changing the thickness of the coating. 2. Preparation and magnetic properties of double magnetic layer Ni_ (80) Fe_ (20) (tout) / Ni_ (80) Fe_ (20) (tin) / Cu) composite structural wires. By changing the thickness of the magnetic layer inside and outside the sample, the composite structure wire with inner and longitudinal circumferential and double circumferential anisotropy magnetic structure was prepared. The results show that the magnetoimpedance curve of the inner and longitudinal circumferential samples is bimodal, which almost coincides with the magneto-impedance curve of the single magnetic layer composite structure with the same total thickness, which indicates that the interlayer interaction is weak in this case. The magnetoimpedance curve of the double annular magnetic structure sample shows a four-peak structure, and the effective anisotropy field Hk of the inner coating is larger than that of the single magnetic layer sample of the same thickness. This is mainly due to the strong interlaminar interaction when the magnetic structure of the inner and outer layers is similar, which leads to the change of the anisotropy field of the coating. 3. The preparation and magnetic properties of [Ni_ (80) Fe_ (20)] n/Cu composite structural wires with fixed monolayer for 10 minutes were studied. The experimental results show that with the increase of the number of layers, the maximum magnetoimpedance ratio of the composite structural wire increases obviously. When n = 1, the coating has longitudinal magnetic anisotropy, which is related to the residual stress and surface morphology of the coating, while at n 鈮，
本文编号：2510918
[Abstract]:In recent years, it has been found that there are many kinds of magnetic interactions in the magnetic materials with composite structures. The geometric structure of the materials and the change of the magnetic layer will lead to the difference of the internal interaction mechanism of the materials, which will affect the use of the materials. On the other hand, because the giant magnetoimpedance (GMI) effect shows very high sensitivity in the low field range, it can not only be used in the field of weak magnetic sensors, but also developed into one of the research methods of magnetic materials with complex structures. In order to further elucidate the interaction in composite wire, Ni_ (80) Fe_ (20) coating was prepared on Cuwire substrate by magnetron splashing. By changing the thickness and number of layers, samples with different geometric structures were designed. The magnetic dipole interaction mechanism in multi-magnetic composite wire and its effect on GMI effect were investigated. The main work of this paper includes the following aspects: first, Ni_ (80) Fe_ (20) / Cu single magnetic layer composite structure wire was prepared, and the effect of coating thickness on magnetoimpedance effect was studied systematically. It is found that the maximum impedance ratio increases at first and then decreases with the increase of the thickness of Ni_ (80) Fe_ (20) layer, and the corresponding axial bias field decreases at first and then increases. It is inferred that this phenomenon is related to the residual compressive stress produced in the preparation process and the surface morphology of the coating. When the thickness of Ni _ (80) Fe_ (20) layer is 485nm, the maximum magnetoresistive ratio of the composite structural wire is the largest and the bias field is the smallest. Therefore, the magnetic properties of the coating can be controlled by changing the thickness of the coating. 2. Preparation and magnetic properties of double magnetic layer Ni_ (80) Fe_ (20) (tout) / Ni_ (80) Fe_ (20) (tin) / Cu) composite structural wires. By changing the thickness of the magnetic layer inside and outside the sample, the composite structure wire with inner and longitudinal circumferential and double circumferential anisotropy magnetic structure was prepared. The results show that the magnetoimpedance curve of the inner and longitudinal circumferential samples is bimodal, which almost coincides with the magneto-impedance curve of the single magnetic layer composite structure with the same total thickness, which indicates that the interlayer interaction is weak in this case. The magnetoimpedance curve of the double annular magnetic structure sample shows a four-peak structure, and the effective anisotropy field Hk of the inner coating is larger than that of the single magnetic layer sample of the same thickness. This is mainly due to the strong interlaminar interaction when the magnetic structure of the inner and outer layers is similar, which leads to the change of the anisotropy field of the coating. 3. The preparation and magnetic properties of [Ni_ (80) Fe_ (20)] n/Cu composite structural wires with fixed monolayer for 10 minutes were studied. The experimental results show that with the increase of the number of layers, the maximum magnetoimpedance ratio of the composite structural wire increases obviously. When n = 1, the coating has longitudinal magnetic anisotropy, which is related to the residual stress and surface morphology of the coating, while at n 鈮，
本文编号：2510918
本文链接：https://www.wllwen.com/shoufeilunwen/boshibiyelunwen/2510918.html
