Magnetic Tunable Nanostructures: Property Characterization and Modeling

本研究的目的是系统地确定纳米级铁磁材料的磁性，并将其与粗晶材料进行比较，以用于电子可调磁性纳米结构。这项研究包括合成、加工和表征它们的磁性随材料变量和外加电场的函数。这些结果，加上模型的补充，将提供对电场、化学和微结构对磁性可调纳米结构性质的影响的基本理解。该合成包括一个八源分子束外延和一个八目标DC/RF溅射沉积系统，具有原位表征能力。它们的磁性质(MS、MR、Hc、Hb、TC、一阶反转曲线等)将使用SQUID和SQUID VSM磁强计、洛伦兹显微镜、FMR和克尔效应光谱对其进行表征。微观结构特征将用LEED、TEM、STEM、X射线衍射仪、洛伦兹和穆斯堡尔光谱进行分析。这些结果将促进对这些纳米结构的理解，并促进它们的技术应用。这是一项德美合作项目，包括德国卡尔斯鲁厄纳米技术研究所、华盛顿特区乔治华盛顿大学和马里兰州盖瑟斯堡的国家标准与技术研究所。如果成功，这项研究的结果不仅将促进对可调纳米结构的理解，还将影响对更广泛类别的磁性纳米结构(包括隧道结、量子点和图案化介质)的磁性行为的理解。未来的努力有望导致各种磁性纳米结构的性能的定制和优化，以便在广泛的技术应用中使用，包括磁性数据存储和传感器设备。研究生、本科生和博士后研究员将受益于获得对高级实验磁测量的理解，并有机会在美国和德国之间进行互访。该项目由土木、机械和制造创新司和国际科学与工程办公室联合资助。

The objective of this research is to systematically determine the magnetic properties of nanoscaled ferromagnetic materials and to compare them to their coarse-grained counterparts for use as electronically tunable magnetic nanostructures. The research involves synthesis, processing, and characterization of their magnetic properties as a function of material variables and applied electric field. These results, complemented by modeling will provide a fundamental understanding of the effects of electric field, chemistry, and microstructure on the properties of magnetic tunable nanostructures. The synthesis involves an eight source molecular beam epitaxy and an eight-target DC/RF sputtering deposition systems, with in-situ characterization capabilities. Their magnetic properties (MS, MR, HC, Hb, and TC, First Order Reversal Curves, etc.) will be characterized using SQUID and SQUID VSM magnetometers, Lorentz microscopy, FMR, and Kerr Effect spectroscopy. The microstructural features will be examined by LEED, TEM, STEM, XRD, Lorentz and Mössbauer spectroscopies. The results will advance the understanding of these nanostructures and promote their technological applications. This is a German-American collaborative effort, involving the Institute of Nanotechnology, Karlsruhe, Germany with George Washington University, Washington, DC and the National Institute of Standards and Technology, Gaithersburg, MD.If successful, the results of this research are expected not only to promote the understanding of tunable nanostructures, but also impact the understanding of the magnetic behavior of the broader class of magnetic nanostructures that include tunnel junctions, quantum dots, and patterned media. Future efforts are expected to lead to tailoring and optimization of the properties of various magnetic nanostructures for their use in a wide range of technological applications, including magnetic data storage and sensor devices. Graduate and undergraduate students and post-doctoral fellows will benefit through acquiring comprehension in advanced experimental magnetic measurements and taking opportunities to exchange visits between the U.S. and Germany. This project is funded jointly by the Division of Civil, Mechanical, and Manufacturing Innovation and the Office of International Science and Engineering.