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采用射频溅射法制备了纳米Fe—In2O3颗粒膜,研究了颗粒膜在低温下的两种特殊磁效应——巨磁电阻效应和磁性弛豫效应。磁电阻测量结果表明,当Fe体积分数为35%时,颗粒膜样品的室温磁电阻变化率(△ρ/ρ0)为4.5%,而在温度T=2K时,∑ρ/ρ0达85%。根据颗粒膜低场磁化率-温度(x-T)关系证实,在一定温度下,颗粒膜中纳米Fe颗粒表现出磁性弛豫效应,当截止温度TB=50K时,颗粒膜的磁特性由超顺磁性转变为铁磁性;在截止温度以上,其饱和磁化强度与温度关系符合Bloch的T^3/2定律。 相似文献
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巨磁电阻(GMR)硬盘磁头由于具有灵敏度高,稳定性好,巴克豪森噪音小等重大优点,使它在信息存储领域引起了一场新的革命。本文报道了一种自旋阀型多层膜「NiFe/Cu/Co/Cu」n的实验研究和理论分析。研究了工艺条件和多层膜结构对巨磁电阻疚的影响,勇于通过对制备条件的优化选择,在常温下得到巨磁阻系数为8%,饱和场强260Oe的优质自旋阀多层膜材料。 相似文献
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对巨磁电阻传感器进行了研究,介绍了巨磁电阻传感器的结构和屏蔽作用,选取电流检测作为巨磁电阻传感器在线性磁场测量的代表,通过对巨磁电阻传感器测试和电流检测的测试,分析了巨磁电阻传感器在磁场线性测量方面的性能优越性,给出了巨磁电阻传感器在磁场线性测量方面的一些注意事项。 相似文献
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磁电子学与巨磁电阻效应的发展和应用 总被引:1,自引:0,他引:1
樊全友 《电子材料与电子技术》2008,(2):13-22
本文在论述磁电子学兴起的基础上,对磁电阻效应的发展历史进行了简要描述。同时,对磁电子学的理论基础进行了重点阐述,并概括了巨磁电阻效应的应用现状。 相似文献
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自从1988年在Fe/Cr多层膜中发现巨磁电阻效应(GMR)以来,GMR薄膜以其丰富多彩的基础研究内涵和在磁记录介质和传感器等领域宽广的应用前景而成为近年来薄膜研究的热点之一.而随后在Co-Cu、Co-Ag等纳米颗粒膜中也发现了巨磁电阻效应,纳米颗粒膜更以其简便的制备工艺而倍受青睐.虽然目前人们对颗粒膜的GMR效应提出了一些理论解释[1,2],但是这些理论不能完全解释实验中所观察到的现象,因此有关颗粒膜的微结构与GMR性能的内在关系仍有待进一步的研究.本文采用多靶磁控溅射方法制备了一系列不同体积分数(25~51vol.%FeCo)的FeCo-Al2O3纳米颗粒膜,研究了其微结构和GMR性能的关系. 相似文献
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由于巨磁电阻效应在基础研究上的重要意义广泛的应用前景,寻找既具有低饱和场,又具有高GMR效应的薄膜材料,已成为当前国际上磁性材料的研究热点之一。本文总结了巨磁电阻材料各类体系的研究方法,分析了其发展方向与研究趋势。 相似文献
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Au/Fe磁性多层膜在纳米颗粒转化过程中的电磁物性在线测量方法 总被引:2,自引:1,他引:1
通过对当前磁性颗粒膜巨磁阻效应的一般研究方法的讨论,分析了当前已存在方法的不足之处,提出了一种利用离子束混合技术在线制备纳米颗粒膜的实验方法,该方法的特点是能够在磁性多层膜转化为纳米颗粒膜的过程中在线测量磁阻和霍尔系数。本文详细介绍了该方法的实施过程,提供了相关的实验结果,证明了该种方法的可行性,并初步讨论了此种方法的应用前景。 相似文献
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采用磁控溅射、光刻、离子束刻蚀和剥离工艺等工艺和方法,制备了多层膜结构的巨磁阻(GMR)生物传感器件,并利用此种传感器来检测甲胎蛋白。在传感器表面通过生物处理固定甲胎蛋白单克隆抗体(McAb1)作为探针,以捕获目标抗原———甲胎蛋白。用直径1μm的超顺磁磁珠标记目标抗原。当传感器表面抗体将目标抗原捕获后,磁珠标记即被固定在GMR传感器的表面。垂直于传感器表面施加230 Oe(1 Am-1=4π×10-3 Oe)的磁场,即可检测到由磁珠产生的信号。本实验对质量浓度为1 ng/mL的甲胎蛋白进行了检测,得到了信号为0.29~0.34Ω的电阻变化值。此种检测方法可用于诊断原发性肝癌。 相似文献
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在硅片上制备结构为Ta/NiFeCr/NiFe/CoFe/Cu/CoFe/IrMn/Ta的IrMn顶钉扎自旋阀薄膜,并最终制成了一组基于此自旋阀结构的GMR磁传感器芯片。利用弱磁场下的退火工艺,改变薄膜易磁化轴的方向,当退火温度为150℃、外加磁场为120Oe时,GMR芯片的矫顽力可以降至0.2Oe以下。同时建立了一种自旋阀自由层的单畴模型,用以解释这一退火效应。利用Mat-lab计算GMR芯片的Meff-H曲线,所得到的计算结果与实验结果一致。所以,自旋阀自由层易磁化轴的方向与GMR磁传感器的性能有着密切的关系。 相似文献
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An overview of processing silicon-germanium (Si-Ge) alloys for various applications is presented here. Several methods of
formation are briefly summarized. In particular, results of preliminary experiments on ion-beam mixing of Si-Ge layered structures
deposited by physical vapor deposition and subsequently ion implanted with varying doses of argon are presented. Different
layered structures have been designed and mixed to obtain optimal process conditions. The ion beam mixing process yields films
with a gradual band-gap variation from 1.12 eV to 0.85 eV, thus allowing quite a wider spectrum of wavelengths to be absorbed.
Rutherford backscattering spectrometry (RBS) has been used to characterize the nature and extent of the mixing of as-deposited
and irradiated films. 相似文献
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提出一种改进的自旋转移矩器件的制备工艺:在电子束曝光形成纳米级图形之后,依次采用离子束刻蚀、带胶绝缘层淀积再正胶剥离的图形转移方法,成功制备了纳米柱状赝自旋阀结构磁性多层膜CoFe/Cu/CoFe/Ta,器件的横向尺寸为140nm×70nm。对该结构进行了电磁学性质的测试:在变化范围为-500~+500Oe(1A/m=4π×10-3 Oe)的外加磁场下,观测到巨磁阻效应;在零外加磁场下,施加垂直于膜平面的电流时,观测到电流诱导的磁化翻转效应,其临界电流密度为108 A/cm2量级。该方法具有工艺步骤少、易于实现的特点,在自旋转移矩器件等纳米级器件的制备中具有广泛的应用前景。 相似文献
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Nanofabrication is possible using focused ion beam technology, but the observation of these structures with the same ion beam is not possible because of its erosion effect. Therefore a general purpose instrument for nanotechnology based on particle optics has to combine an ion and an electron beam. The objective lens, the final lens above the specimen, has to focus both beams on the specimen. An objective lens that combines magnetic and electrostatic fields has been designed for this purpose. Its aberration coefficients allow a 1 nm ion beam and a 0.3 nm electron beam. 相似文献
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Magnetically engineered spintronic sensors and memory 总被引:3,自引:0,他引:3
Parkin S. Xin Jiang Kaiser C. Panchula A. Roche K. Samant M. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》2003,91(5):661-680
The discovery of enhanced magnetoresistance and oscillatory interlayer exchange coupling in transition metal multilayers just over a decade ago has enabled the development of new classes of magnetically engineered magnetic thin-film materials suitable for advanced magnetic sensors and magnetic random access memories. Magnetic sensors based on spin-valve giant magnetoresistive (GMR) sandwiches with artificial antiferromagnetic reference layers have resulted in enormous increases in the storage capacity of magnetic hard disk drives. The unique properties of magnetic tunnel junction (MTJ) devices has led to the development of an advanced high performance nonvolatile magnet random access memory with density approaching that of dynamic random-access memory (RAM) and read-write speeds comparable to static RAM. Both GMR and MTJ devices are examples of spintronic materials in which the flow of spin-polarized electrons is manipulated by controlling, via magnetic fields, the orientation of magnetic moments in inhomogeneous magnetic thin film systems. More complex devices, including three-terminal hot electron magnetic tunnel transistors, suggest that there are many other applications of spintronic materials. 相似文献
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M.-Dolores Cubells-Beltrán C. Reig A. De Marcellis E. Figueras A. Yúfera B. Zadov E. Paperno S. Cardoso P.P. Freitas 《Microelectronics Journal》2014
Giant Magnetoresistance (GMR) based technology is nowadays the preferred option for low magnetic fields sensing in disciplines such as biotechnology or microelectronics. Their compatibility with standard CMOS processes is currently investigated as a key point for the development of novel applications, requiring compact electronic readout. In this paper, such compatibility has been experimentally studied with two particular non-dedicated CMOS standards: 0.35 μm from AMS (Austria MicroSystems) and 2.5 μm from CNM (Centre Nacional de Microelectrònica, Barcelona) as representative examples. GMR test devices have been designed and fabricated onto processed chips from both technologies. In order to evaluate so obtained devices, an extended characterization has been carried out including DC magnetic measurements and noise analysis. Moreover, a 2D-FEM (Finite Element Method) model, including the dependence of the GMR device resistance with the magnetic field, has been also developed and simulated. Its potential use as electric current sensors at the integrated circuit level has also been demonstrated. 相似文献