共查询到20条相似文献，搜索用时 15 毫秒
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W. Heimbrodt P. J. Klar S. Ye M. Lampalzer C. Michel S. D. Baranovskii P. Thomas W. Stolz 《Journal of Superconductivity and Novel Magnetism》2005,18(3):315-320
The magneto-transport properties of granular paramagnetic–ferromagnetic GaAs:Mn/MnAs hybrids have been studied. Positive and
negative magnetoresistivity can be observed in the paramagnetic matrix as well as in the GaAs:Mn/MnAs hybrid system. The experimental
results and the respective relevant interactions are discussed. A phenomenological explanation from a microscopic point of
view is presented. It is suggested that the paramagnetism of the matrix plays a major role in the magneto-resistive behavior
of the hybrids, in contrast to diamagnetic–ferromagnetic hybrids where the magnetoresistance (MR) is dominated by the ferromagnetism
of the clusters. 相似文献
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Lizhen Huang;Changlong Wang;Ping Liu;Shasha Wang;Haige Tan;Zhanfeng Liu;Yan Feng;Xiang Ma;Junjie Wu;Zhe Sun;Shengtao Cui;Yalin Lu;Bin Xiang; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(43):2403002
Van der Waals (vdW) magnetic materials have broad application prospects in next-generation spintronics. Inserting magnetic elements into nonmagnetic vdW materials can introduce magnetism and enhance various transport properties. Herein, the unconventional magnetic and magneto-transport phenomena is reported in Ni0.28TaSeS crystal by intercalating Ni atoms into nonmagnetic 2H-TaSeS matrix. Magnetic characterization reveals a canted magnetic structure in Ni0.28TaSeS, which results in an antiferromagnetic (AFM) order along the c-axis and a ferromagnetic (FM) moment in the ab-plane. The presence of spin-flop (SF) behavior can also be attributed to the canted magnetic structure. Temperature-dependent resistivity exhibits a metallic behavior with an abrupt decrease corresponding to the magnetic transition. Magneto-transport measurements demonstrate a positive magnetoresistance (MR) with a plateau that is different from conventional magnetic materials. The field-dependent Hall signal exhibits nonlinear field dependence when the material is in magnetically ordered state. These unconventional magneto-transport behaviors are attributed to the field-induced formation of a complex spin texture in Ni0.28TaSeS. In addition, it further investigated the angle dependence of MR and observed an unusual fourfold anisotropic magnetoresistance (AMR) effect. This work inspires future research on spintronic devices utilizing magnetic atom-intercalated quasi-2D materials. 相似文献
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Tunneling magneto-resistance (TMR) in magnetic heterostructures is a very important phenomenon for future spin-electronic devices. This paper presents our TMR studies on two epitaxial magnetic tunnel junctions (MTJs): GaMnAs/AlAs/GaMnAs ferromagnetic/ nonmagnetic semiconductor MTJs, and MnAs/AlAs/MnAs ferromagnetic-metal/ semiconductor MTJs, which are both compatible with semiconductor device technology. 相似文献
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Pauly M Dayen JF Golubev D Beaufrand JB Pichon BP Doudin B Bégin-Colin S 《Small (Weinheim an der Bergstrasse, Germany)》2012,8(1):108-115
A co-tunneling charge-transfer process dominates the electrical properties of a nanometer-sized \"slice\" in a nanoparticle network, which results in universal scaling of the conductance with temperature and bias voltage, as well as enhanced spintronics properties. By designing two large (10 μm) electrodes with short (60 nm) separation, access is obtained to transport dominated by charge transfer involving \"nanoslices\" made of three nanoparticles only. Magnetic iron oxide nanoparticle networks exhibit a magnetoresistance ratio that is not reachable by tunneling or hopping processes, thereby illustrating how such a size-matched planar device with dominant co-tunneling charge-transfer process is optimal for realizing multifunctional devices with enhanced change of conductance under external stimulus. 相似文献
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Guy Koplovitz Darinka Primc Oren Ben Dor Shira Yochelis Dvir Rotem Danny Porath Yossi Paltiel 《Advanced materials (Deerfield Beach, Fla.)》2017,29(17)
There is an increasing demand for realizing a simple Si based universal memory device working at ambient temperatures. In principle, nonvolatile magnetic memory can operate at low power consumption and high frequencies. However, in order to compete with existing memory technology, size reduction and simplification of the used material systems are essential. In this work, the chiral‐induced spin selectivity effect is used along with 30–50 nm ferromagnetic nanoplatelets in order to realize a simple magnetic memory device. The vertical memory is Si compatible, easy to fabricate, and in principle can be scaled down to a single nanoparticle size. Results show clear dual magnetization behavior with threefold enhancement between the one and zero states. The magnetization of the device is accompanied with large avalanche like noise that is ascribed to the redistribution of current densities due to spin accumulation inducing coupling effects between the different nanoplatelets. 相似文献
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Hammam Al‐Bustami Guy Koplovitz Darinka Primc Shira Yochelis Eyal Capua Danny Porath Ron Naaman Yossi Paltiel 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(30)
There is an increasing demand for the development of a simple Si‐based universal memory device at the nanoscale that operates at high frequencies. Spin‐electronics (spintronics) can, in principle, increase the efficiency of devices and allow them to operate at high frequencies. A primary challenge for reducing the dimensions of spintronic devices is the requirement for high spin currents. To overcome this problem, a new approach is presented that uses helical chiral molecules exhibiting spin‐selective electron transport, which is called the chiral‐induced spin selectivity (CISS) effect. Using the CISS effect, the active memory device is miniaturized for the first time from the micrometer scale to 30 nm in size, and this device presents memristor‐like nonlinear logic operation at low voltages under ambient conditions and room temperature. A single nanoparticle, along with Au contacts and chiral molecules, is sufficient to function as a memory device. A single ferromagnetic nanoplatelet is used as a fixed hard magnet combined with Au contacts in which the gold contacts act as soft magnets due to the adsorbed chiral molecules. 相似文献
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Joseph Finley Chia‐Hao Lee Pinshane Y. Huang Luqiao Liu 《Advanced materials (Deerfield Beach, Fla.)》2019,31(2)
Ferrimagnetic materials combine the advantages of the low magnetic moment of an antiferromagnet and the ease of realizing magnetic reading of a ferromagnet. Recently, it was demonstrated that compensated ferrimagnetic half metals can be realized in Heusler alloys, where high spin polarization, zero magnetic moment, and low magnetic damping can be achieved at the same time. In this work, by studying the spin–orbit torque induced switching in the Heusler alloy Mn2Ru1? x Ga, it is found that efficient current‐induced magnetic switching can be realized in a nearly compensated sample with strong perpendicular anisotropy and large film thickness. This work demonstrates the possibility of employing compensated Heusler alloys for fast, energy‐efficient spintronic devices. 相似文献
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用射频磁控溅射制备了由FeCo纳米磁性颗粒分布在SiO2绝缘介质中形成的（Fe65Co35）0.4（2SiO2）0.58纳米颗粒膜。通过低温磁场回火得到很好的软磁性,易轴矫顽力低至143Am^-1;并呈现很好的面内单轴磁各向异性,各向异性场为3820Am^-1;电阻率高达13.4mΩ·cm。样品的磁谱（磁导率与频率的关系）显示出很好的高频特性：在工作频率f〈0.7GHz时,复数磁导率的实部μ′〉100,FMR频率达1.8GHz,说明样品有高的截止频率,显示出在高频器件及抗电磁干扰技术方面具有很好的应用前景。用铁磁共振实验证明此样品中好的高频软磁性是由于实现了颗粒间的铁磁性交换耦合所致。 相似文献
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Songtian Li Konstantin V. Larionov Zakhar I. Popov Takahiro Watanabe Kenta Amemiya Shiro Entani Pavel V. Avramov Yuya Sakuraba Hiroshi Naramoto Pavel B. Sorokin Seiji Sakai 《Advanced materials (Deerfield Beach, Fla.)》2020,32(6):1905734
Graphene-based vertical spin valves (SVs) are expected to offer a large magnetoresistance effect without impairing the electrical conductivity, which can pave the way for the next generation of high-speed and low-power-consumption storage and memory technologies. However, the graphene-based vertical SV has failed to prove its competence due to the lack of a graphene/ferromagnet heterostructure, which can provide highly efficient spin transport. Herein, the synthesis and spin-dependent electronic properties of a novel heterostructure consisting of single-layer graphene (SLG) and a half-metallic Co2Fe(Ge0.5Ga0.5) (CFGG) Heusler alloy ferromagnet are reported. The growth of high-quality SLG with complete coverage by ultrahigh-vacuum chemical vapor deposition on a magnetron-sputtered single-crystalline CFGG thin film is demonstrated. The quasi-free-standing nature of SLG and robust magnetism of CFGG at the SLG/CFGG interface are revealed through depth-resolved X-ray magnetic circular dichroism spectroscopy. Density functional theory (DFT) calculation results indicate that the inherent electronic properties of SLG and CFGG such as the linear Dirac band and half-metallic band structure are preserved in the vicinity of the interface. These exciting findings suggest that the SLG/CFGG heterostructure possesses distinctive advantages over other reported graphene/ferromagnet heterostructures, for realizing effective transport of highly spin-polarized electrons in graphene-based vertical SV and other advanced spintronic devices. 相似文献