茂金属催化剂及其在聚烯烃领域中的应用

本文介绍了茂金属催化剂的特点和分类，以及茂金属催化剂在聚烯烃合成及工艺方面的应用。     

金属蜂窝的开发、发展及应用

系统介绍了金属蜂窝的结构特性，综述了金属蜂窝在汽车、飞机、能源、化工以及由其制成的复合材料中的用途，剖析了其应用产品具有的优势和不足，展示了金属蜂窝的发展方向和应用前景。     

石墨烯负载金属与化合物的研究进展

石墨烯是一种以碳元素为基本原子经过sp²杂化，π-π共轭而紧密堆积的单层二维蜂窝状晶格结构，具有优异的物理和化学性质，在多个领域具有优异性能而成为研究热点。因石墨烯比表面积大，可作为基体，所形成的石墨烯基复合材料是石墨烯应用领域中的一个重要研究方向，可分为负载型和增强型。本文主要综述了石墨烯负载金属(单金属、双金属和三金属)/化合物(金属氧化物、金属硫化物和金属氟化物)复合材料近几年的制备方法和应用现状。此外，通过对上述复合材料的总结，得出金属/化合物的颗粒尺寸和形状、分散程度以及石墨烯片层的堆叠等问题会影响性能的结论，并对石墨烯负载金属/化合物复合材料能够在磁性、力学、微波吸收以及导热等领域所具有的应用前景进行展望。     

金属有机非线性光学材料

本文介绍了非线性光学的简史，非线性光学材料的分类及应用，简述了金属有机非线性光学材料的原理，从分子工程和晶体工程的角度讨论了金属有机非线性光学材料的结构与性质的关系，综述了目前已研究的金属有机化合物和金属有机聚合物的二阶、三阶非线性光学材料，二阶非线性光学材料按目前所做的工作可以分成二大类：一类是含有芳香基或杂环的过渡金属羰基化合物；一类是含有二茂铁基和吸电子基的共轭体系化合物。三阶非线性光学材料的研究工作主要集中在酞菁类的金属配合物上，本文对金属有机化合物作为非线性光学材料的独特之处进行了总结，并对金属有机非线性光学材料的前景作了展望。     

用等离子体源离子注入法提高金属表面耐蚀性

对等离子体源离子注入和常规离子注入进行了对比，介绍了等离子体注入在提高金属表面硬度和抗腐蚀性能上的应用，讨论了电子回旋共振等离子体源离子注入在提高表面腐蚀抗力中的前景。     

贮氢合金应用研究近况

本文综述了贮氢合金的应用研究近况。包括贮氢合金在氢的贮存，运输，净化，压缩，热泵，催化和二次电池等应用领域的现状和发展，指出了目前存在的问题及新型贮氢材料的发展方向。     

新型常温金属除油剂的制备与应用

叙述了一种新型常温金属除油剂的制备和应用，其与传统的除油剂相比，具有节能，安全，高效，价廉等特点。     

材料表面激光熔覆研究进展

激光熔覆技术是一种先进的表面改性技术，具有广阔的应用前景。本文详细评述了激光熔覆技术的研究和应用，其中包括熔覆工艺，理论模型、材料体系及其熔覆形成的冶金组织特征和性能，同时，指出了存在的问题和今后努力的方向。     

防锈包装的机理与应用

通过外界环境对金属产品的影响以及金属产品锈蚀机理的论述，提出了常用的各种防锈材料和包装材料，阐明了防锈包装的方法的应用。     

金属空心微球的制备及应用现状

金属空心微球不仅具有一般金属空心球的结构和性能等特点，而且还具有小尺寸的独特优势，可望在微电子、微系统和生命科学等诸多前沿领域发挥重大的作用。介绍了金属空心微球的制备和应用现状，并对存在的问题进行了的讨论。     

1996—1997年磁性功能材料进展

综述了磁性功能材料在１９９７￣１９９７年的间的若干新进展。内容包括：（１）高饱和磁化强度铁氧体／金属东薄膜和稀土合金／金属薄膜，（２）巨Ｈａｌｌ效应磁性材料，（３）钠米磁性功能材料，（４）巨磁光旋转效应材料，（５）低磁场庞磁电阻材料。     

石墨烯在量子霍尔电阻中的应用

基于砷化镓的量子霍尔电阻自然基准需要在约1.5K的温度条件下运行,存在成本高和操作复杂等诸多问题。随着石墨烯材料独特电性能的发现,因其可以在约4.2K的温度复现量子霍尔效应而成为制作量子霍尔电阻的理想材料。各国专家围绕石墨烯在电学计量领域的应用开展了大量的工作,取得了可喜的进展。对当前石墨烯在量子霍尔电阻中应用的进展和存在的问题进行了总结,并对未来的发展进行了展望。     

Giant spin Hall effect in perpendicularly spin-polarized FePt/Au devices

Conversion of charge current into pure spin current and vice versa in non-magnetic semiconductors or metals, which are called the direct and inverse spin Hall effects (SHEs), provide a new functionality of materials for future spin-electronic architectures. Thus, the realization of a large SHE in a device with a simple and practical geometry is a crucial issue for its applications. Here, we present a multi-terminal device with a Au Hall cross and an FePt perpendicular spin injector to detect giant direct and inverse SHEs at room temperature. Perpendicularly magnetized FePt injects or detects perpendicularly polarized spin current without magnetic field, enabling the unambiguous identification of SHEs. The unprecedentedly large spin Hall resistance of up to 2.9 mOmega is attributed to the large spin Hall angle in Au through the skew scattering mechanism and the highly efficient spin injection due to the well-matched spin resistances of the chosen materials.     

Metrology and microscopic picture of the integer quantum Hall effect

Since 1990, the integer quantum Hall effect has provided the electrical resistance standard, and there has been a firm belief that the measured quantum Hall resistances are described only by fundamental physical constants--the elementary charge e and the Planck constant h. The metrological application seems not to rely on detailed knowledge of the microscopic picture of the quantum Hall effect; however, technical guidelines are recommended to confirm the quality of the sample to confirm the exactness of the measured resistance value. In this paper, we give our present understanding of the microscopic picture, derived from systematic scanning force microscopy investigations on GaAs/(AlGa)As quantum Hall samples, and relate these to the technical guidelines.     

Hall effect in polycrystalline semiconductors

A phenomenological theory of the Hall effect in polycrystalline semiconductors is elaborated which makes it possible to interpret reasonably the experimental results obtained from Hall effect measurements. The theory is based on the analysis of the Hall effect in the individual grains and intergrain domains forming the polycrystalline semiconductor. Explicit calculations of the expressions for the Hall constant, Hall scattering coefficient and Hall and conductivity mobilities are performed for wide-gap n-type semiconductors. It is shown that the models of Volger and of Berger are special limiting cases of the theory presented and that the model of Petritz can be extended to the problems of the Hall constant and the Hall mobility in a simple way.The expressions presented for the Hall constant, the Hall scattering coefficient and the Hall mobility represent generalized expressions from which the corresponding expressions for single-crystal semiconductors can be derived.     

Adiabatic photo-steering theory in topological insulators

Feasible external control of material properties is a crucial issue in condensed matter physics. A new approach to achieving this aim, named adiabatic photo-steering, is reviewed. The core principle of this scheme is that several material constants are effectively turned into externally tunable variables by irradiation of monochromatic laser light. Two-dimensional topological insulators are selected as the optimal systems that exhibit a prominent change in their properties following the application of this method. Two specific examples of photo-steered quantum phenomena, which reflect topological aspects of the electronic systems at hand, are presented. One is the integer quantum Hall effect described by the Haldane model, and the other is the quantum spin Hall effect described by the Kane–Mele model. The topological quantities associated with these phenomena are the conventional Chern number and spin Chern number, respectively. A recent interesting idea, time-reversal symmetry breaking via a temporary periodic external stimulation, is also discussed.     

Calculating the Effects of Longitudinal Resistance in Multi-Series-Connected Quantum Hall Effect Devices

Many ac quantized Hall resistance experiments have measured significant values of ac longitudinal resistances under temperature and magnetic field conditions in which the dc longitudinal resistance values were negligible. We investigate the effect of non-vanishing ac longitudinal resistances on measurements of the quantized Hall resistances by analyzing equivalent circuits of quantized Hall effect resistors. These circuits are based on ones reported previously for dc quantized Hall resistors, but use additional resistors to represent longitudinal resistances. For simplification, no capacitances or inductances are included in the circuits. The analysis is performed for many combinations of multi-series connections to quantum Hall effect devices. The exact algebraic solutions for the quantized Hall resistances under these conditions of finite ac longitudinal resistances provide corrections to the measured quantized Hall resistances, but these corrections do not account for the frequency dependences of the ac quantized Hall resistances reported in the literature.     

Optimization of QHE-devices for metrological applications

In the framework of an European project aiming at the realization of a system for the calibration of capacitance standards based on the quantum Hall effect (QHE), optimized QHE devices for the metrological application as dc as well as ac standards of resistance are developed. The present paper describes the dc characterization of a large number of devices with different layouts, contact configurations, carrier concentrations, and mobilities. The results demonstrate the influence of the device parameters on the critical current, the width of the quantized plateaus, the longitudinal voltages along the device and the quantized Hall resistance. Recommendations are given for the layout and mobility of QHE devices in view of their use as dc standards of resistance     

Ferromagnetic resonance driven by spin transfer torque

We study spin-torque-driven ferromagnetic resonance (ST-FMR) in point contacts. Point contacts as small as a few nanometers in size are used to inject microwave currents into F/N/F spin valves where two ferromagnetic (F) layers are separated by a nonmagnetic (N) metal spacer. High densities of injected currents produce the spin-transfer torque on magnetic moments and drive FMR in the F-layers. The resonance is detected electrically when a small rectified dc voltage appears across the point contact. Here we focus on the origin of this rectified signal and study ST-FMR in point contacts to spin valves with different ferromagnets (Py and Co) and single ferromagnetic (Py) films, as well as in spin-valve wires patterned by electron beam lithography. We find that this voltage can be explained by the resistance variations which originate from giant magnetoresistance in point contacts to spin valves and involve effects of anisotropic magnetoresistance and extraordinary Hall effect on the propagation of microwave currents in continuous F-films and microwires.     

Derivation of Transverse Spin-Wave Dynamics from a Kinetic Equation in a Rotating Reference Frame

The Hall effect in single crystal BSCCO whiskers has been measured, with the current flowing along the a and b crystallographic directions. The ab-plane anisotropy of the Hall anomaly is found. The magnitude of the anomaly, as well as its anisotropy, are strongly affected by the structural defects.