GOALI: Magnetic Thin-Films for Data Storage

这是一个GOALIE提案，涉及路易斯安那州立大学的一位物理学家与惠普实验室和希捷科技的合作者之间的合作。该研究涉及磁性数据存储设备，目前该设备包含由磁性和非磁性材料构成的薄膜巨磁阻（GMR）传感器。材料的特殊组合提高了对磁性钻头的灵敏度，这是通过电阻的变化来检测的。学生将被送往惠普和希捷实验室培养薄膜，表征其磁性和输运特性，并开发可转移的方法来比较不同机构培养的薄膜。在路易斯安那州立大学，薄膜的生长特性将使用扫描隧道显微镜进行评估，而磁性特性将使用磁光克尔效应进行评估。电子能带结构将在LSU先进微结构和器件同步加速器中心（CAMD）进行表征，使用一系列基于同步加速器的技术，如角度和自旋分辨光电发射，价带二色性，以及使用显示分析仪的费米表面映射。研究的材料包括单晶衬底上的三维过渡金属和合金薄膜，如Cu(001)，或原位生长的氧化物。理论研究表明，在自旋隧道器件中使用半金属材料（如Fe3O4和CrO2）可以提高灵敏度；这些材料也将被调查。该项目将为凝聚态物理基础和技术领域的本科生和研究生提供优秀的培训。这是一个GOALIE提案，涉及路易斯安那州立大学的一位物理学家与惠普实验室和希捷科技的合作者之间的合作。计算机磁盘驱动器中的磁传感器现在是通过将原子薄的磁性和非磁性薄膜结合成层状结构来制造的，这种结构具有更高的灵敏度，可以缩小比特尺寸，增加容量。然而，薄膜的基本性质与大块材料有很大的不同。本项目着重于新电子结构的实验表征及其与磁性改善的关系。路易斯安那州立大学的学生将在工业和大学设施中生长薄膜，并表征这些设备的磁性和电特性。在路易斯安那州立大学进行的研究包括使用扫描隧道显微镜对薄膜生长特性进行原子尺度表征，以及通过观察偏振光在反射时旋转的程度来进行磁性表征。在路易斯安那州立大学高级微结构和器件中心（CAMD）同步加速器，学生们将通过监测在强软x射线照射下从表面发射的电子的能量和角度来评估新的电子结构。这些数据将与电子结构的理论模型进行比较，提供开发新磁性材料过程中所需的反馈。该项目将为凝聚态物理基础和技术领域的本科生和研究生提供优秀的培训。

Kurtz9802278This is a GOALIE proposal involving a collaboration between a physicist at Louisiana State University and collaborators at Hewlett-Packard Laboratories and Seagate Technology. The research relates to magnetic data storage devices that currently incorporate thin film giant magnetoresistive (GMR) sensors, constructed from magnetic and non-magnetic materials. Particular combinations of materials give rise to enhanced sensitivity to magnetic bits which are detected by changes in resistance. Students will be sent to HP and Seagate Laboratories to grow films, characterize their magnetic and transport properties, and develop transferable methods to compare films grown at different institutions. At LSU, the growth characteristics of the films will be evaluated with scanning tunneling microscopy, while magnetic characteristics will be evaluated using the magneto-optical Kerr effect. The electronic band structures will be characterized at the LSU Synchrotron Center for Advanced Microstructures and Devices (CAMD), using an array of synchrotron based techniques such as angle- and spin-resolved photoemission, valence-band dichroism, and Fermi surface mapping using a display analyzer. The materials studied include 3d transition metals and alloy films on single-crystal substrates such as Cu(001), or on oxides grown in situ. Theoretical studies suggest that improved sensitivity may be achieved by using half-metallic materials, such as Fe3O4 and CrO2, in spin-tunneling devices; such materials will be investigated as well. The project will provide excellent training for undergraduate and graduate students in fundamental and technical areas of condensed matter physics.%%%This is a GOALIE proposal involving a collaboration between a physicist at Louisiana State University and collaborators at Hewlett-Packard Laboratories and Seagate Technology. Magnetic sensors in computer disk drives are now being fabricated by combining atomically-thin magnetic and non-magnetic films into layered structures with improved sensitivity, allowing bit sizes to shrink and capacity to increase. The fundamental properties of the thin films differ significantly from bulk materials, however. This project focuses on experimental characterization of the new electronic structures and their relationship to the improved magnetic performance. LSU students will grow films in industrial and university facilities and characterize the magnetic and electrical characteristics of these devices. Research conducted at LSU involves atomic-scale characterization of the film growth properties using scanning-tunneling microscopy and magnetic characterization by observations of the degree to which polarized light is rotated on reflection. At the LSU Center for Advanced Microstructures and Devices (CAMD) synchrotron, students will evaluate the new electronic structures that arise by monitoring the energies and angles of electrons emitted from the surfaces under intense soft x-ray irradiation. These data will be compared with theoretical models of the electronic structure, providing the feedback that is required in the process of developing new magnetic materials. The project will provide excellent training for undergraduate and graduate students in fundamental and technical areas of condensed matter physics.