摘要铁磁/反铁磁薄膜体系的交换偏置效应在自旋阀结构和磁性隧道结领域得到很广泛的应用。本文利用高真空磁控溅射平台制作了FeCo/FeMn和FeNi/FeMn两种样品,然后通过VSM对的磁滞回线等磁性能进行研究,对交换偏置效应进行验证。67234
所得结论:通过对FeMn/FeNi薄膜体系的XRD图像和FeMn薄膜的EDS分析,得到FeMn织构取向和Mn原子含量都满足生产交换偏置的要求。强磁场中生长的FeNi/FeMn薄膜体系室温磁滞回线中,能够明显区分出难易轴,即存在各向异性;但易磁化轴没有偏移,即没有生成交换偏置;但弱磁场中,室温磁滞回线却没有呈现出各向异性,分析得到可能是磁场施加未到位,导致薄膜无法产生交换偏置。
在实验中我们意外发现了缓冲层Cu可以诱导FeCo产生各向异性,可以进一步探究缓冲层厚度、生长工艺对FeCo各向异性影响和其内在的影响机制。
毕业论文关键词:交换偏置;铁磁;反铁磁;各向异性
毕业设计说明书(论文)外文摘要
Title The effect of nonmagnetic dilution in ferromagnet/antiferromagnet by magnetron sputtering on the exchange bias
Abstract
The exchange bias in FM/AFM bilayers has been widely used in spin valve structures and magnetic tunnel junctions.In this paper we manufacture two kinds of samples, FeCo/FeMn and FeNi/FeMn, by high vaccum magnetron sputtering platform.Then we investigate hysteresis loop and verify the exchange bias.
Conclusions: with the analysis of XRD of FeMn/FeNi films system and the EDS of FeMn films, we found both of the FeMn texture orientation and the atom contents of Mn can meet the request to production of the exchange bias.
Among hysteresis loops of FeMn/FeNi films system growing in intensive magnetic field at room temperature, we can easily distinguish easy axis of magnetization and hard axis of magnetization from the M-H curves, which means the existence of anisotropy; However, easy axis of magnetization doesn’t move, which means no production of the exchange bias; But the hysteresis loops growing in weak magnetic field at room temperature doesn’t present the anisotropy. The true reason may be the improper exertion of magnetic field which can’t produce the exchange bias.
During the process of experiment, we occasionally found the Cu buffer layer can induce FeCo with anisotropy. So the effect of thickness of buffer layer, growth technology on the anisotropy of FeCo and its internal mechanism deserves a deeper research.
Keywords: Exchange bias;Ferromagnet; Antiferromagnet;Anisotropy
目 录
1 绪论 1
1.1 课题背景 1
1.2 铁磁/反铁磁交换偏置的基本特征 2
1.3 交换偏置理论解释模型 5
1.4 交换偏置中反铁磁稀释效应的研究 8
1.5选题目的以及研究内容 9
2 实验材料的制备和研究方法 10
2.1 前期工作 10
2.2 实验样品制备和研究方法 11
3 铁磁/反铁磁薄膜样品磁性能分析 14
3.1 FeCo/FeMn样品的M-H曲线 14
3.2 FeCo/FeMn样品的磁导率曲线 16
3.3 FeMn/FeNi样品的M-H曲线和磁导率曲线 17
结论