双合成反铁磁结构及其对自旋阀巨磁电阻效应的影响

用直流磁控溅射方法制备了双合成反铁磁结构Co₉₀Fe₁₀(5 nm)/Ru(x nm)/Co₉₀Fe₁₀(3 nm)/Ru(y nm)/Co₉₀Fe₁₀(5 nm)(x=0.45,0.45,1.00; y=0.45,1.00,1.00)的系列样品,并对样品的性能及其作为钉扎层对自旋阀巨磁电阻(GMR)效应的影响进行了研究 关键词： 双合成反铁磁 自旋阀 巨磁电阻     

两步法制备的自旋阀巨磁电阻效应研究

采用新的磁控溅射两步法沉积自旋阀多层膜,不仅交换耦合作用大大增强,而且可以提高磁电阻比值和降低层间耦合作用.得到磁电阻比值～26%,交换耦合场～28kA/m,层间耦合场～01kA/m.自旋阀的下部(缓冲层(Ta)/自由层(NiFe)/中间隔离层(Cu))在低氩气压下沉积、上部(被钉扎层(NiFe)/反铁磁钉扎层(FeMn)/覆盖层(Ta))则在高氩气压下沉积.前者保证了自旋阀具有强(111)晶体织构,平整的NiFe/Cu界面和致密的Cu层,抑制了层间耦合作用;后者则促进小尺寸磁畴生长和增加NiFe/FeM 关键词：     

自旋阀中的各向异性磁电阻效应

采用平面霍尔效应测量方法，对Ta(8nm)/NiFe(7nm)/Cu(24nm)/NiFe(44nm)/FeMn(14nm)/Ta(6nm)自旋阀多层膜进行了研究.结果表明，在样品中存在着自由层和被钉扎层之间的各向异性磁电阻的“混合”效应.与通常所采用的磁电阻测量方法相结合，平面霍尔效应的测 量可以给出自旋阀中各向异性磁电阻以及自由层和被钉扎层的磁矩随外场变化的更多信息. 关键词： 自旋阀 各向异性磁电阻 平面霍尔效应     

第七讲 自旋阀巨磁电阻效应及其应用

自旋阀巨磁电阻具有工作磁场小，灵敏度高、频率特生好、信噪比高等优点，成为新一代高度密度读出砂的首选材料，在计算机信息存贮和高灵敏传感器方面有着广阔的应用前景。     

第五讲 自旋极化输运及隧道巨磁电阻效应

简要回顾了利用量子隧道效应测定铁磁金属传导电子自旋极化率的研究历史，综述了自旋极化电子隧穿产应导致的“铁磁金属／非磁绝缘体／铁磁金属”三层平面型隧道结中的巨磁电阻效应以及“铁磁金属／非磁绝缘体”颗粒膜系统中的隧穿类型巨磁电阻效应的研究进展。     

巨磁电阻效应实验仪的研制与应用

阐述了巨磁电阻效应实验原理、实验内容和实验方法,该仪器可测量巨磁电阻阻值与磁感应强度关系,并与正常磁电阻、坡莫合金磁电阻特性进行比较,仪器还提供巨磁电阻传感器特性测量及系列应用实验供教学使用.     

自旋输运和巨磁电阻--自旋电子学的物理基础之一

介绍磁性纳米结构和锰氧化物中电子的自旋极化输运和巨磁电阻效应，它们是新近发展的自旋电子学的物理基础之一．着重讨论的是以下三方面的基本物理图像：磁多层结构的巨磁电阻，铁磁隧道结的隧穿磁电阻，掺杂锰氧化物的庞磁电阻效应．     

磁电阻效应的研究进展

介绍了磁电阻效应的研究状况和进展,总结了铁磁金属的磁电阻效应、磁性多层膜和颗粒膜的巨磁阻效应、磁隧道电阻效应及氧化物铁磁体的超大磁阻效应的理论模型,并简要分析了磁电阻效应的物理机制。     

具有室温巨隧道磁电阻效应与高自旋极化率的新材料

回顾了隧道磁电阻效应发展简史及其应用，报道了锌铁氧体／氧化铁二相纳米复合材料在室温具有巨磁隧道电阻效应的实验结果，该实验结果表明锌铁氧体是具有高自旋极化率的一类新材料，值得进一步开展相关的研究工作。     

纳米微粒系统中的巨磁电阻效应

重点介绍含有铁磁纳米微颗粒系统中的巨磁电阻效应，例如颗粒膜，快淬纳米复相固体居磁电阻效应与铁磁组成，颗粒尺寸，形状的依赖性。     

自旋阀与多层膜巨磁电阻的特性测量及比较

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.     

Magnetic behaviour investigation on symmetric spin valves of Co／Cu／NiFe and NiFe／Cu／Co

In this paper,we have obtained and investigated the magnetic behaviours of the ferromagnetic layer in the symmetric spin valves of Co/Cu/NiFe and NiFe/Cu/Co by measuring with a vibrating sample magnetometer and analysing in terms of the multi-domain Ising models.It has been found that some magnetic layer can have quite different magnetic behaviours in different structures of spin valves,depending on the properties of the under-layer.In our investigation,we have found that the magnetic behaviour of a Co layer depends mainly on the magnetization of the under-layer,whereas this is not the case for the NiFe layer.     

Negative tunnelling magnetoresistance in spin filtering magnetic junctions with spin-orbit coupling

We present theoretical calculations of spin transport in spin filtering magnetic tunnelling junctions based on the Landauer-Buttiker formalism and taking into account the spin-orbit coupling(SOC).It is shown that spin-flip scattering induced by SOC is stronger in parallel alignment of magnetization of the ferromegnet barrier(FB) and the ferromagnetic electrode than that in antiparallel case.The increase of negative tunnelling magnetoresistance with bias is in agreement with recent experimental observation.     

La0.4Ca0.6MnO3系统中Mn位Fe和Cr掺杂效应的比较性研究

利用固相反应法制备了Mn位Fe³⁺和Cr³⁺掺杂的系列锰氧化物La_0.4Ca_0.6(Mn_1-x(y)B_x(y))O₃ (B=Fe³⁺ (0≤x≤0.1); Cr³⁺ (0≤y≤0.1)) 多晶样品,研究了掺杂对样品输运性质的影响.实验结果表明两种离子具有截 关键词： 锰氧化物 反铁磁 磁电阻效应     

自旋电子学研究与进展

自旋电子学是最近几年在凝聚态物理中发展起来的新学科分支,它研究在固体中自旋自由度的有效控制和操纵,在金属和半导体中自旋极化、自旋动力学、自旋极化的输运和自旋电子检测.由于它在信息存储方面的重大应用前景,受到学术界和工业界的高度重视.文章扼要地介绍了自旋电子学发展的历程和发展中的最重要的发现.最近几年,最奇特的发现和最重要的应用莫过于巨磁电阻,薄膜领域纳米技术的迅速发展使巨磁电阻的应用变成可能.作为磁记录头它已使硬磁盘的记录密度提高到170Gbit/in2.动态随机存储器MRAM的研究已实现16Mbit的存储密度.     

Transport phenomena in spin caloritronics

The interconversion between spin, charge, and heat currents is being actively studied from the viewpoints of both fundamental physics and thermoelectric applications in the field of spin caloritronics. This field is a branch of spintronics, which has developed rapidly since the discovery of the thermo-spin conversion phenomenon called the spin Seebeck effect. In spin caloritronics, various thermo-spin conversion phenomena and principles have subsequently been discovered and magneto-thermoelectric effects, thermoelectric effects unique to magnetic materials, have received renewed attention with the advances in physical understanding and thermal/thermoelectric measurement techniques. However, the existence of various thermo-spin and magneto-thermoelectric conversion phenomena with similar names may confuse non-specialists. Thus, in this Review, the basic behaviors, spin-charge-heat current conversion symmetries, and functionalities of spin-caloritronic phenomena are summarized, which will help new entrants to learn fundamental physics, materials science, and application studies in spin caloritronics.     

Validity and Limitation of Semi-Classical Approaches to Giant Magnetoresistance in Magnetic Multilayers

The validity and limitation of semi-classical theories on giant magnetoresistance in magnetic multilayers are discussed on the basis of fundamental quantum statistical mechanics.     

Temporal evolution of spin accumulation in nonlocal spin valves

A temporal evolution of spin signals has been observed in nanoscale Co/Cu nonlocal spin valves. The spin diffusion length of Cu increases from ∼300 to ∼350 nm measured at 295 K over a 50-day period in the ambient environment after the fabrication of the devices. This is attributed to a gradual oxidation in the regions near the side surfaces of the Cu channel, where Co impurities are implanted during the fabrication. An increase of spin injection polarization is also found and attributed to the change of oxidation states at the interfaces.