Effect of Defects on the Magnetic Properties of 2D Films Using Patterned Substrates

小行星9623283 该项目将研究长度接近2 nm的结构缺陷如何影响磁性能。 该项目具有技术 重要性，因为对记录介质中更高存储密度的需求预期将磁簇尺寸推到2nm半径以下。 一套新颖的图案化钨基板将用于进行这样的研究。 这些表面由一个周期性的阶梯组成，每一步都有一个原子高。 通过控制生长条件，可以迫使二维铁膜从衬底台阶生长出来，以产生等间距的一维磁线。 这些线之间的间隙在二维磁膜中起着不完美的作用。由于两种线宽度（2至10个原子 和线分离（1至20个原子） 可以 独立变化，我们将探讨有限的线宽度的影响和孤立的线之间的耦合铁膜的磁性。这项工作将结合使用高分辨率低能电子衍射，表面磁光克尔， 效果， 和扫描隧道显微镜。 原子缺陷对磁性薄膜性能的影响将 发挥重要作用， 下一代高密度记录介质。对更高存储密度的需求预计将推动磁簇的直径降低到6到10个原子的大小。 因此，重要的是要了解限制磁性薄膜包含少于100个原子如何影响磁性能。我们设计了一种新的技术来生长薄（3至10个原子宽）平行磁线阵列。 这些导线将被用来研究导线厚度和导线间距如何影响其磁性能。 将研究产生磁矩所需的临界导线厚度以及相邻导线对单个导线磁性能的影响。 ***

9623283 Conrad This project will investigate how structural defects on length scales approaching 2 nm will affect the magnetic properties. The project has technological importance because the demand for higher storage densities in recording media is expected to push magnetic clusters sizes below a 2 nm radius. A novel set of patterned tungsten substrates will be used to carry out such a study. These surfaces consist of a periodic staircase with each step one atom high. By controlled growth conditions, 2-dimensional iron films can be forced to grow out from the substrate steps to produce equal spaced one-dimensional magnetic wires. The gaps between these wires play the role of imperfections in a 2-dimensional magnetic film. Since both wire width (2 to 10 atoms and wire separation (1 to 20 atoms) can be independently varied, we will explore finite wire width effects and coupling between isolated wires on the iron film's magnetic properties. The work will be carried out using a combination of high resolution Low Energy Electron Diffraction, Surface Magneto-Optical Kerr effect, and Scanning Tunneling Microscopy. %%% The influence of atomic defects on magnetic film properties will play an important role in developing the next generation of high density recording media. The demand for higher storage densities is expected to push the diameter of magnetic clusters down to sizes of 6 to 10 atoms. It is therefore important to understand how magnetic properties are affected by limiting the magnetic films to contain less than 100 atoms. We have devised a novel technique to grow arrays of thin (3 to 10 atoms wide) parallel magnetic wires. These wires will be used to study how wire thickness and wire separation influence their magnetic properties. The critical wire thickness required to develop a magnetic moment and the effects of neighboring wires on th e magnetic properties of an individual wire will be studied. ***