FRG: Ballistic Magnetoresistance in Ferromagnetic Nanocontacts

该补助金的一个主要目标是研究基于磁性过渡金属（Ni和Co）以及半金属磁铁矿系统的技术重要磁性纳米结构中磁性纳米接触的弹道磁阻（BMR）。纳米接触将使用电沉积技术沿着与纳米尺寸的尖锐尖端使用电化学方法制造。一个主要的目标是进行系统的研究接触直径，局部域结构和组成的纳米接触BMR的影响。该研究结果将构成对自旋极化电子在纳米尺度磁收缩中输运的基本理解。接触直径将被选择为从扩散到弹道电子传输机制。BMR纳米接触的发展将极大地使当前的数据存储容量从当前的每平方英寸千兆位范围增加到每平方英寸兆兆位范围。纽约州立大学布法罗分校和亚利桑那州立大学州立大学之间的合作研究涉及参与NIST使用扫描电子显微镜与偏振分析（SEMPA）对磁性结构进行成像。对支撑在固体基底上的微加工纳米接触的研究发现了一系列有用的应用，例如在超声波中的独立单元。高灵敏度磁传感器以及新型生物传感器，其中给定的分子可以产生其自己独特的电子签名。沿着对研究生和本科生的实验室培训，外联活动包括为布法罗地区内城高中的少数民族和女学生举办为期五周的暑期学徒方案。

A major objective of the grant is to investigate ballistic magnetoresistance (BMR) in magnetic nanocontacts in technologically important magnetic nanostructures based on the magnetic transition metals (Ni and Co) as well as the half-metallic magnetite system. The nanocontacts will be made using electrodeposition techniques along with nanometer size sharp tips fabricated using electrochemical methods. A principal objective is to make a systematic study of the effects of contact diameter, local domain structure and the composition of the nanocontacts on BMR. The results from the study will constitute fundamental understanding of spin-polarized electron transport across nanometer-sized magnetic constrictions. The contact diameters will be selected spanning from diffusive to ballistic electron transport regimes. The development of BMR nanocontacts would greatly enable the current data storage capacity to be increased from the current Gbits per square inch range to the terabits per square inch range. The collaborative research between SUNY Buffalo and Arizona State University involves participation at NIST for imaging magnetic structures using Scanning Electron Microscopy with Polarization Analysis (SEMPA).The research on microfabricated nanocontacts supported on a solid substrate find a range of useful applications as stand-alone units such as in ultra-high sensitivity magnetic sensors as well as novel biological sensors where a given molecule can be made to give its own unique electronic signature. Along with the laboratory training of researchers at graduate and undergraduate levels, outreach activities include a five-week summer apprentice program for minorities and women students from Buffalo-area inner city high schools.