半金属纳米材料的自旋极化输运性能研究

项目名称： 半金属纳米材料的自旋极化输运性能研究

项目编号： No.11274370

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 杨海涛

作者单位： 中国科学院物理研究所

项目金额： 85万元

中文摘要： 半金属材料一般具有较高的居里温度和近100%的高自旋极化率，将会成为理想的自旋电子注入源。因此，半金属材料的深入研究必将推动自旋电子学的快速发展。众多研究已经表明半金属材料的尺度、维度的减小以及颗粒边界对其自旋极化输运性能有很大的影响，也是提高半金属材料自旋极化率和低场磁电阻的有效途径。本研究利用高温有机液相法制备出尺寸和形状可控的单分散半金属纳米材料，利用高压原位输运测试系统深入研究尺寸、形状、颗粒边界、压力、温度和磁场对其自旋极化输运性能的影响，揭示半金属纳米颗粒的自旋极化输运规律，应用无规熔丝网络模型和非平衡格林函数的第一性原理方法模拟计算半金属纳米材料的自旋极化输运性能，结合NanoProbe-STM-SEM联合系统对单个纳米线和纳米颗粒(>30nm)的输运性能测试，揭示半金属纳米材料的自旋极化输运机制，进而在理论上通过设计输运通道微结构构型研究增强室温及低场磁电阻的可能途径。

中文关键词： 半金属；纳米材料；自旋极化；输运性能；

英文摘要： Half-metallic material generally has a high Curie temperture and perfect spin polarization of nearly 100% from theoretical prediction and are considered as an ideal,potenial spin injector. So the investigation on half-metallic materials must enhanced the development of spintronics.Many research results have revealed that the scale, dimension, and particle border have a strong influence on the spin-polarization transport properties, which is also the effective way to improve the spin polarizability and the low-field magnetoresistance effect. In this project, the monodisperse hal-metallic nanomaterials with a controlled size and shape are synthesized by a high-temperature organic solution method. The influence of size,shape,particle border,temperature,pressure, and magnetic field on their spin-polarization transport properites are to be investigated to reveal the transport law of half-metallic namomaterials.Combined with the transport properties of the single nanowire and nanoparticles (>30nm) by the NanoProbe-STM-SEM measure system, the spin-polarization mechanics of half-mettallic nanomaterials are to be revealed by employing radom fuse network model and non-equilibrium Green's functiontechniques. Furthermore, the possible way to improve the magnetoresistance effect at room temperature and lower magneitc field w

英文关键词： half-metal；nanomaterial；spin-polarization；transport properties；