共查询到19条相似文献,搜索用时 578 毫秒
1.
将NiFe/PtMn双层膜生长在(Ni0.81Fe0.19)1-xCrx种子层材料上,通过改变种子层中Cr的原子含量,系统的研究了NiFe/PtMn双层膜中PtMn晶粒尺寸和织构对交换偏置的影响.对退火270℃,5h后的NiFe/PtMn双层膜磁性的研究表明,PtMn织构强弱对交换偏置场的影响不明显,而PtMn的晶粒尺寸是影响交换偏置场的主要因素,PtMn颗粒的相干长度在11.3nm左右时得到了较大的交换偏置场.
关键词:
NiFe/PtMn双层膜
交换偏置场 相似文献
2.
研究了在铁磁(NiFe)/反铁磁(FeMn)双层膜之间,交换偏置的形成过程和热稳定性,特别是NiFe/FeMn的交换偏置作用与FeMn层晶粒尺寸的关系.和以前作者不同的是,本文方法采用非磁性Ni-Fe-Cr合金作缓冲层材料,改变Cr的含量就可以获得不同晶粒尺寸的反铁磁FeMn层.实验表明,晶粒尺寸较小的FeMn产生较强的铁磁/反铁磁交换偏置场;但是,对于较大晶粒的FeMn层,出现交换偏置作用所要的临界厚度较小.这符合Mauri提出的理论模型.交换偏置场的热稳定性实验表明,具有较大晶粒尺寸的FeMn层给出较
关键词:
交换偏置
热稳定性
反铁磁
晶粒尺寸 相似文献
3.
采用磁控溅射方法制备了分别以Ta和Ta/Cu作为缓冲层的一系列NiFe/FeMn双层膜.实验发现,以Ta为缓冲层的NiFe/FeMn双层膜的交换偏置场比以Ta/Cu为缓冲层的NiFe/FeMn双层膜的交换偏置场大.测量了这两种双层膜的织构、表面粗糙度和表面成分.结果表明,以Ta/Cu为缓冲层时,Cu在NiFe层的上表面偏聚是造成NiFe/FeMn双层膜交换偏置场降低的重要原因.
关键词:
NiFe/FeMn
交换偏置场
织构
表面粗糙度 相似文献
4.
利用表面磁光克尔效应和铁磁共振对分子束外延生长的Fe/Fe50Mn50双层膜的交换偏置场和矫顽力进行了研究,实验结果表明,当反铁磁层厚度小于55nm时 ,不出现交换偏置,而当大于这一厚度时,出现交换偏置;大约在7nm时,达到极大值.随着 反铁磁层厚度的继续增大,偏置场和矫顽力随Fe50Mn50膜厚的增大 而下降.铁磁共振实验结果表明样品的磁性存在单向各向异性.并对上述结果进行了讨论.
关键词:
分子束外延
50Mn50')" href="#">Fe/Fe50Mn50
双层膜
交换偏置 相似文献
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6.
采用一种新的种子层材料:(Ni081Fe019)1-xCrx,通过改变种子层中Cr原子的含量,使得在其上生长的NiFeFeMn双层膜的织构和晶粒尺寸产生极大的差异,系统研究了NiFeFeMn双层膜中FeMn晶粒尺寸和织构对交换偏置的影响.实验结果表明,在FeMn的γ相(111)织构较好的前提下,交换偏置场的大小与织构的差异没有关系;FeMn的晶粒尺寸对交换偏置场有很大影响,较小的反铁磁层晶粒对交换偏置场有利,过大的反铁磁层晶粒不利于交换偏置场.将(Ni081Fe019)05Cr05与传统的种子层材料Ta进
关键词:
交换偏置
晶粒尺寸
织构
种子层 相似文献
7.
研究了磁场诱导生长的BiFeO3/Ni18Fe19磁性双层膜中 的交换偏置及其热稳定性. 结果表明: BiFeO3/Ni18Fe19双层膜中的交换偏置场Hex未表现出明显的磁练习效应. 在负饱和磁场等待过程中, BiFeO3/Ni18Fe19双层膜磁滞回线的前支和后支曲 线都随着在负饱和磁场中等待时间tsat的增加向正场方向偏移. 交换偏置场Hex的大小随着等待时间tsat的增加而减小, 矫顽力Hc基本不变. 交换偏置场Hex的大小随测量温度Tm的升高变化不明显, 表现出良好的热稳定性; 但矫顽力Hc随Tm的升高而显著减小. 良好的热稳定性应该来源于铁电性和反铁磁性间的共同耦合作用.
关键词:
多铁性
磁性薄膜
交换偏置
热稳定性 相似文献
8.
采用磁控溅射方法制备了以Pt为缓冲层和保护层的具有垂直各向异性(Pt/Co)n/ FeMn多层膜.研究结果表明,多层膜的垂直交换偏置场Hex和反铁磁层厚度的关 系与其具有平面各向异性的交换偏置场随反铁磁层厚度变化趋势相近.随着铁磁层调制周期 数的增加,垂直交换偏置场Hex相应减小,并且与铁磁层的调制周期数近似成反 比关系.(Pt/Co)3/FeMn的垂直交换偏置场Hex已经达到22.3kA/m.为
关键词:
交换偏置
垂直各向异性
多层膜 相似文献
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11.
Cr1-x
Fe
x
and Mn1-x
Fe
x
films were prepared at room temperature by thermal coevaporation at a deposition rate of about 25 Å/min. It was found that an amorphous phase can be obtained for Cr1-x
Fe
x
(0.25<x<0.60) films, while a metastable-Mn-type phase was observed for Mn1-x
Fe
x
(x<0.70) films. The influence of the structure on the magnetic properties has been studied. The amorphization ability of the two systems was discussed in terms of thermodynamic considerations. 相似文献
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13.
以NiFeNb为种子层,制备(Ni79Fe21)1-xNbx(5nm)/(Ni79Fe21) (20nm)/Ta(3nm)系列膜,并对其颗粒大小、 磁滞回线及表面粗糙度等进行测量,探讨种子层中Nb含量x对坡莫合金磁滞回线的影响.结果 表明,以NiFeNb作种子层能更好地改善坡莫合金的微结构. Nb含量为23%时的磁滞回线有最 小的最大磁能积、矫顽力.种子层影响坡莫合金磁滞回线的一个重要原因是脱附激活能等因 素造成种子层具有不同的表面粗糙度,进而使坡莫合金具有不同的微结构和磁性能.
关键词:
NiFeNb种子层
坡莫合金
磁滞回线
粗糙度 相似文献
14.
15.
基于多种实验手段和能带计算的方法, 对四元合金Fe2Co1-xCrxSi的晶体结构、 磁性、输运性质及能带结构进行了研究. 研究发现, 随着Cr的增加, 合金Fe2Co1-xCrxSi保持了高度有序结构, 逐渐从Hg2CuTi结构的Fe2CoSi 过渡到L21结构的Fe2CrSi; 由于次晶格网络的破坏, 居里温度逐渐下降; 系列合金的分子磁矩呈现线性下降, 符合半金属特性; 剩余电阻比率与原子占位有序程度密切相关, 呈现两端大、 中间小的特点. 在Cr替代Co的过程中, 材料半金属能隙逐渐打开, 表现半金属特征. 同时费米能级从Fe2CoSi半金属能隙的价带顶上移至Fe2CrSi能隙的导带底. 最大的能隙宽度出现在x= 0.75处, 这表明四元合金有可能成为具有更高自旋极化率和更强抗干扰能力的自旋电子学材料. 相似文献
16.
Ramis Mustafa Öksüzo?lu Mustafa Y?ld?r?mHakan Ç?nar Erwin HildebrandtLambert Alff 《Journal of magnetism and magnetic materials》2011,323(13):1827-1834
A systematic investigation has been done on the correlation between texture, grain size evolution and magnetic properties in Ta/Ni81Fe19/Ir20Mn80/Co90Fe10/Ta exchange bias in dependence of Ta buffer and NiFe seed layer thickness in the range of 2-10 nm, deposited by pulsed DC magnetron sputtering technique. A strong dependence of 〈1 1 1〉 texture on the Ta/NiFe thicknesses was found, where the reducing and increasing texture was correlated with exchange bias field and unidirectional anisotropy energy constant at both NiFe/IrMn and IrMn/CoFe interfaces. However, a direct correlation between average grain size in IrMn and Hex and Hc was not observed. L12 phase IrMn3 could be formed by thickness optimization of Ta/NiFe layers by deposition at room temperature, for which the maximum exchange coupling parameters were achieved. We conclude finally that the coercivity is mainly influenced by texture induced interfacial effects at NiFe/IrMn/CoFe interfaces developing with Ta/NiFe thicknesses. 相似文献
17.
Ni
x
Fe1−x
(0.22 ≤x ≤ 0.62) alloy films were grown by electrodeposition technique. A shift in diffraction peaks of NiFe and Ni3Fe was detected with increasing Ni content. The highest positive magnetoresistance ratio was detected as 5% in Ni0.51Fe0.49. Positive and negative anisotropic magnetoresistance were observed in longitudinal and transverse geometries respectively.
The highest anisotropic magnetoresistance ratio of 9.8% was also detected in Ni0.51Fe0.49. The angular variation of magnetoresistance was studied. Magnetisation loop curves show that NiFe alloy films have a linear
decreasing anisotropy constant with increasing Ni deposit content and show a decreasing behavior of coercivity which indicates
soft magnetic property with increasing Ni deposit content 相似文献
18.
Minghua Li Gan HanLei Ding Xiaocui WangYang Liu Chun FengHaicheng Wang Guanghua Yu 《Journal of magnetism and magnetic materials》2012,324(1):1-3
The anisotropic magnetoresistance (AMR) of a Ta (5 nm)/MgO (3 nm)/Ni81Fe19 (10 nm)/MgO (2 nm)/Ta (3 nm) film with MgO-Nano Oxide Layer (NOL) increases dramatically from 1.05% to 3.24% compared with a Ta (5 nm)/Ni81Fe19 (10 nm)/Ta (3 nm) film without the MgO-NOL layer after annealing at 380 °C for 2 h. Although the MgO destroys the NiFe (1 1 1) texture, it enhances the specular electron scattering of the conduction electrons at the NOL interface and suppresses the interface reactions and diffusion at the Ta/NiFe and NiFe/Ta interfaces. The NiFe (1 1 1) texture was formed after the annealing, resulting in a higher AMR ratio. X-ray photoelectron spectroscope results show that Mg and Mg2+ were present in the MgOx films. 相似文献
19.
《Current Applied Physics》2020,20(7):883-887
Voltage control magnetism is one of the most energy efficient pathway towards magnetoelectric (ME) device. Ionic liquid gating (ILG) method has already shown impressive manipulation power at the IL/electrode interface to influence the structure, orbital as well as spin of the electrode materials. As key material in anisotropy magnetoresistance sensor and spin valve heterostructure, the permalloy Ni0.81Fe0.19 was utilized as the electrode to investigate the ILG induced magnetic anisotropy change. In this work, we realized magnetic anisotropy control in Au/[DEME]+[TFSI]-/Ni0.81Fe0.19 (2.5 nm)/Ta heterostructure via ILG caused electrostatic doping. This is evidenced in situ reversible ferromagnetic field (Hr) shift with electron spin resonance (ESR) spectrometer. Aiming at the question whether the charge accumulation at the ionic liquid interface is the main control mechanism at low voltage, we carefully tested the relationship between the change of resonance field and the amount of surface charge. It was found that these two had a good linear relationship between −1 V and +1 V. Defining the linear parameter as A whose value is 28.7 mT m2/Col. Unlike previously reported chemical regulation of Co, this article used ionic liquids to physically regulate NiFe, which has not been studied in the previous ionic liquid regulation. And NiFe has a narrower resonance line width for easy reference to microwave devices. In addition, It also has a stronger ferromagnetic signal than Co, which can be more easily detected as a sensor device. Therefore, this system is more promising. The ILG control NiFe may lead to a new kind of magnetoelectric sensor devices and path a new way to low energy consumption spintronics. 相似文献