共查询到19条相似文献,搜索用时 250 毫秒
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阐述了巨磁电阻效应的机理,利用AA002系列巨磁电阻(GMR)器件测量了单个巨磁电阻的阻值与磁场磁感应强度的关系以及AA002系列巨磁电阻(GMR)器件的输出电压与外磁场的关系,研究了巨磁电阻效应的特性,并设计了巨磁电阻器件在物理实验教学中的实用性比较广泛的系列实验. 相似文献
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报告了作者对Gd_5Ge_4合金样品进行了磁化和电输运测量的研究结果,实验表明,磁化强度随外磁场的增加而出现台阶式跳跃,磁转变的可逆性与温度存在有密切的关联.在由磁场导致的磁转变附近电阻率随着磁场的增加亦表现出台阶式磁电阻现象,并在不同温区表现出正负不同的磁电阻效应,4.2K时呈现正磁电阻效应,而在16和20K时呈现出负磁阻效应,即铁磁相的阻值小于反铁磁相的阻值.结果证明了在Gd_5Ge_4中存在的典型相分离特征,从而在磁场诱导下发生了反铁磁到铁磁的转变,并对这种奇异磁电阻效应的物理机制进行了讨论. 相似文献
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介绍磁性多层膜中自旋极化输运和巨磁电阻效应,简述自旋阀巨磁电阻与多层膜巨磁电阻在材料组成结构和工作原理方面的区别,利用和改造现有的高校物理实验室中的实验仪器并设计简易的实验电路测量这两种类型的巨磁电阻的磁敏特性,并根据实验测量的结果将这两种传感器在其灵敏度和测量范围上进行比较和研究. 相似文献
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介绍了利用ZDY型自动磁场成型机、电脑化X-Y记录仪、计算机、HSZ-1数字磁强计等仪器测量巨磁电阻材料磁电阻的方法,同时对低温的测量装置进行了研究。 相似文献
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Pei-Sen Li 《中国物理 B》2022,31(3):38502-038502
For convenient and efficient verification of the magnetoresistance effect in graphene spintronic devices, vertical magnetic junctions with monolayer graphene sandwiched between two NiFe electrodes are fabricated by a relatively simple way of transferring CVD graphene onto the bottom ferromagnetic stripes. The anisotropic magnetoresistance contribution is excluded by the experimental result of magnetoresistance (MR) ratio dependence on the magnetic field direction. The spin-dependent transport measurement reveals two distinct resistance states switching under an in-plane sweeping magnetic field. A magnetoresistance ratio of about 0.17 % is obtained at room temperature and it shows a typical monotonic downward trend with the bias current increasing. This bias dependence of MR further verifies that the spin transport signal in our device is not from the anisotropic magnetoresistance. Meanwhile, the I—V curve is found to manifest a linear behavior, which demonstrates the Ohmic contacts at the interface and the metallic transport characteristic of vertical graphene junction. 相似文献
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介绍了金属磁性多层膜的微结构和磁结构的研究进展,简要综述了磁性多层膜的结构与巨磁电阻(GMR)之间的关系 相似文献
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A. Nogaret N. Overend B. L. Gallagher P. C. Main M. Henini C. H. Marrows M. A. Howson S. P. Beaumont 《Physica E: Low-dimensional Systems and Nanostructures》1998,2(1-4)
We have investigated ballistic magnetoresistance effects in a two dimensional electron gas subjected to a periodic magnetic field that alternates in sign. The magnetic field was produced by a submicron ferromagnetic grating, made of either nickel or cobalt stripes, which was fabricated at the surface of the heterostructure. We observe giant magnetoresistance effects due to the channelling of electrons along lines of zero magnetic field orientated perpendicular to the current. Our semiclassical model accounts in great detail for all features in the magnetoresistance. 相似文献
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N. V. Vorob’eva A. N. Lachinov Jan Genoe A. A. Lachinov V. M. Kornilov 《Bulletin of the Russian Academy of Sciences: Physics》2009,73(1):15-18
The contribution of spin-polarized electrons, injected from a ferromagnet to a polymer, to the giant magnetoresistance has been investigated for the ferromagnet-polymer-nonmagnetic metal system. It is established that, at complete depolarization of injected electrons, magnetic field does not affect the conductivity of the system. The electric field effect (significant decrease in the threshold magnetic field) on the parameters of giant injection magnetoresistance is established. 相似文献
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L. I. Koroleva R. V. Demin J. Warczewski J. Krok-Kowalski T. Mydlarz A. Gilewski A. Pacyna 《JETP Letters》2000,72(11):561-564
A giant magnetoresistance, reaching 74% in a magnetic field of 38 T at 3 K, was observed in the CuCr1.6Sb0.4S4 semiconductor spinel. The magnetic properties point to the existence of a magnetic two-phase state in this compound. The giant magnetoresistance was explained by the existence of the magnetic two-phase state due to strong s-d exchange. 相似文献
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A. A. Gorbatsevich V. V. Kapaev Yu. V. Kopaev I. V. Kucherenko O. E. Omel’yanovskii V. I. Tsebro 《Journal of Experimental and Theoretical Physics》2001,93(4):833-845
A new phenomenon, viz., field-asymmetric transverse magnetoresistance of a doped asymmetric quantum-size structure discovered in a magnetic field parallel to the heteroboundary planes, is studied experimentally and theoretically. The magnetoresistance asymmetry relative to the field direction, which is independent of the direction of transport current, is observed when a lateral electric field is embedded in the structure with the help of alloyed metallic contacts. In the theoretical part of the paper, it is shown that the contribution to current, which is asymmetric in the magnetic field, can be consistently described in the framework of the theory of spontaneous current states and photovoltaic effect in systems without an inversion center; the reason behind the emergence of this current is associated with the asymmetry of the energy spectrum of charge carriers relative to the quasimomentum. It is shown that the change in the size and shape of Fermi contours in a magnetic field determines the magnitude of the strong negative magnetoresistance associated with the intersubband scattering under investigation and is found to be responsible for the emergence of a qualitatively new effect mentioned in the title of this paper. 相似文献
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Magnetotransport properties and magnetocaloric effects of Mn1.95Cr0.05Sb0.95Ga0.05 compound
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The magnetotransport properties and magnetocaloric effects of the compound Mn_{1.95}Cr_{0.05}Sb_{0.95}Ga_{0.05} have been studied. With decreasing temperature, a spontaneous first-order magnetic phase transition from ferrimagnetic (FI) to antiferromagnetic (AF) state takes place at T_s=200K. A metamagnetic transition from the AF to FI state can be induced by an external field, accompanied by a giant magnetoresistance effect of 57%. The magnetic entropy changes are determined from the temperature and field dependence of the magnetization using the thermodynamic Maxwell relation. Mn_{1.95}Cr_{0.05}Sb_{0.95}Ga_{0.05} exhibits a negative magnetocaloric effect, and the absolute values of ΔS_M^{max}(T,ΔH) are 4.4, 4.1, 3.6, 2.8 and 1.5 J/(kg·K) for magnetic field changes of 0-5T, 0-4T, 0-3T, 0-2T and 0-1T, respectively. 相似文献
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The validity and limitation of semi-classical theories on giant magnetoresistance in magnetic multilayers are discussed on the basis of fundamental quantum statistical mechanics. 相似文献