第六讲 巨磁电阻效应在信息存储等领域中的应用

用巨磁电阻材料构成磁电子学新器件，已开始在信息存储领域成功地获得了应用，文章介绍了用于计算机硬磁盘驱动器巨磁电阻磁头和巨磁电阻随机存储器，描述了它的工作原理，性能特点及发展趋势，指出巨磁电阻材料在传感器方面的应用也令人瞩目，有着广阔的市场前景。     

磁电子学讲座 第二讲 掺杂稀土锰氧化物的巨磁电阻效应

介绍了掺杂稀土锰氧化物的巨磁电阻效应研究概况和最新进展．在综合目前实验和理论研究结果的基础上，对在掺杂稀土锰氧化物材料中引起巨磁电阻效应的物理机制进行了探讨．对这一材料的应用前景和需要做的工作进行了讨论     

在锰钙钛石中晶格对磁电阻的影响

掺杂锰钙钛石中的超巨磁电阻响应的发现激励人们在更大的范围内寻找新的巨磁电阻材料．研究表明，在烧绿石（Ａ２Ｍ２Ｏ７）、尖晶石（ＡＢ２Ｘ４）以及磁铁矿（Ｆｅ３Ｏ４）结构中，都有可能观察到巨磁电阻响应．从技术应用的角度讲，这些过渡金属化合物似乎比掺杂锰钙钛...     

掺杂稀土锰氧化物的巨磁电阻效应

介绍了掺杂稀土锰氧化物的巨磁电阻效应研究概况和最新进展，在综合目前实验和理论研究结果的基础上，对在掺杂稀土锰氧化物材料中引起巨磁电阻效应的物理机制进行了探讨，对这一材料的应用前景和需要做的工作进行了讨论。     

磁电子学讲座 第七讲 自旋阀巨磁电阻效应及其应用

自旋阀巨磁电阻材料具有工作磁场小、灵敏度高、频率特性好、信噪比高等优点，成为新一代高密度读出磁头的首选材料，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．     

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．     

利用碳纳米管中的自旋和轨道自由度

电子自旋在信息处理中可以被作为二元变量使用，分别表示为自旋↑和↓，一个成功的例子是：计算机硬盘的读出头．这一器件的工作原理是基于巨磁电阻效应，即磁电阻大小的自旋取向依赖性．巨磁电阻现象的发现者AlbertFert和PeterGriinberg获得了2007年度诺贝尔物理奖．对于自旋态的操控和探测构成了自旋电子学的基础．在自旋电子学器件中，     

Fe-Ag金属颗粒膜的巨磁电阻

采用量子唯象模型研究金属颗粒膜巨磁电阻的特性．在计算散射截面时，考虑了颗粒内各杂质原子之间的相位相干性．依据实验报告提供的颗粒尺寸分布的数据，推导了巨磁电阻依赖于颗粒尺寸及其分布和外磁场的函数表示式．对样品Fe-Ag的计算结果表明，其磁电阻随外磁场的变化和颗粒尺寸的分布有关；在某个颗粒尺寸标度D₀，磁电阻出现极大值，尺寸标度D₀的大小与外加磁场、样品材料和制备条件有关 关键词：     

磁性材料新近进展

磁性材料是应用广泛、品种繁多的一类重要的功能材料，20世纪90年代以后发展十分迅速．稀土-3d过渡族磁性合金材料，如稀土水磁、巨磁致收缩材料、巨磁热效应材料，磁光效应材料等，以及非晶，纳米微晶磁性材料相继问世．1988年巨磁电阻效应的发现已获广泛应用，如读出磁头、传感器以及磁随机存储器等，并发展成为自旋电子学的新学科．文章简要介绍了近年来磁性材料的一些新进展。     

Co/Cu92Mn8/Co结构中的低场巨磁电阻研究

对三明治结构的Co/Cu/Co和Co/Cu₉₂Mn₈/Co系列的巨磁电阻效应进行了研究,发现两者的巨磁电阻均随中介层厚度作周期性振荡,但是接近反相.作为与Co/Cu/Co系统的比较,发现若在Cu基中稀释Mn原子,巨磁电阻随外磁场变化的曲线会有非常大的改变,同时饱和场或开关场也有较大的下降,这意味着有可能为Co/Cu金属多层膜的巨磁电阻的实用化研究开辟出一条新的思路. 关键词：     

非线性响应对巨磁阻的影响

从非线性Kubo公式出发,计算了磁三明治结构的巨磁阻效应.通过考虑 电子运动垂直平面方向,自旋反射和界面处导电电子的散射作用,研究了电流在平面的巨磁 阻量子效应,发现非线性效应在不同程度上影响巨磁阻效应.在零温附近,温度参数对巨磁阻影响很小,而外场偏压的影响相对较大.     

Performance of conformal guided mode resonance filters

Guided mode resonance (GMR) filters are highly functional micro-optics capable of narrowband spectral filtering. GMR devices have previously been demonstrated on flat substrates using a wide range of materials and configurations. In this Letter, we apply a soft lithographic technique followed by the deposition of dielectric layers to generate GMR filters on a concave lens surface. Resonances of the resulting conformal GMR filters are experimentally measured and characterized, and the results are compared to the performance of similar GMR filters fabricated on flat surfaces.     

非线性响应对自旋阀磁电阻的影响

从非线性Kubo公式出发,考虑电子自旋相关体散射, 研究了自旋阀结构磁电阻效应.发现非线性响应在不同程度上影响巨磁阻效应.在零温附近,温度参数对磁电阻影响较小,而外加偏压对磁电阻的影响相对较大.     

Isotopic dependence of the giant monopole resonance in the even-A 112-124Sn isotopes and the asymmetry term in nuclear incompressibility

The strength distributions of the giant monopole resonance (GMR) have been measured in the even-A Sn isotopes (A=112-124) with inelastic scattering of 400-MeV alpha particles in the angular range 0 degrees -8.5 degrees . We find that the experimentally observed GMR energies of the Sn isotopes are lower than the values predicted by theoretical calculations that reproduce the GMR energies in 208Pb and 90Zr very well. From the GMR data, a value of Ktau = -550 +/- 100 MeV is obtained for the asymmetry term in the nuclear incompressibility.     

Propagation properties of beams generated by Gaussian mirror resonator in uniaxial crystals

Based on the paraxial vectorial theory of beams propagating in uniaxially anisotropic media, we have derived the analytical propagation equations of beams generated by Gaussian mirror resonator (GMR) in uniaxial crystals, and given the typical numerical example to illustrate our analytical results. Due to the anisotropy crystals, the ordinary and extraordinary beams originated by incident beams generated by GMR propagate with different diffraction lengths, thus the linear polarization state and axial symmetry of the incident beams generated by GMR do not remain during propagating in crystals.     

Modelling the sensitivity of infrared emissivity of magnetic thin films to giant magnetoresistance

The correlation between emissivity and giant magnetoresistance (GMR) in magnetic thin films is investigated at infrared (IR) wavelengths using a thin-film model of emissivity. The sensitivity of emissivity to GMR is shown to depend upon film thickness, and agrees excellently with bulk-material results for films thicker than the material skin depth. However, for films thinner than the skin depth the sensitivity to GMR is shown to weaken. In addition, at mid-to-far IR wavelengths the spectral dependence of the correlation is investigated using a modified Drude-type expression for the refractive index combined with the thin-film model. This is applied to a multilayered GMR material, and the sensitivity of emissivity to GMR is shown to have a similar spectral dependence to that of the magnetorefractive effect. An analytical interpretation in terms of skin depth is also developed at long wavelengths, and shown to agree excellently with thin-film simulations.     

Optimizing the quality factor of a wideband guided-mode resonance biosensor

This work studies the effect of the biochemical molecular layer on the quality factor of guided-mode resonance (GMR) filter of an ultrasensitive label-free biosensor. A GMR biosensor with a narrower bandwidth has a higher sensitivity but requires much higher accuracy in its fabrication process. In this study, we have managed to present a GMR filter with a narrow bandwidth that requires less precision by controlling the thickness of the biochemical molecule layer, which increases the Q factor by up to three times.     

Giant Multipole Resonances in an excited core model

The Giant Multipole Resonances (GMR) of (sd)-shell nuclei have been calculated in an excited core model where the low lying excited states of the valence nucleons are coupled to the GMR of the ¹⁶O-core by means of a separable two-body residual nucleon-nucleon interaction. The results of such a calculation of the GMR of ²⁰Ne and ²²Ne are compared with the available experimental data; the characteristic details of the strength distribution can be reproduced rather satisfactorily.     

Effect of GMR and Magnetization Reversal on Microwave Absorption

Low-field microwave absorption has been measured as a function of magnetic field in a series of thin film structures exhibiting or not exhibiting the giant magnetoresistance effect (GMR). Although a close correlation has been found between the microwave absorption and GMR, an additional absorption due to magnetization reversal is shown to have substantial effect on the overall microwave response.