GOALI: Si-doped Co/Pd Multilayers on ITO Seedlayers for Perpendicular Magnetic Recording Media

该提案描述了涉及由实验学家、理论家和行业联络人组成的互补团队的研究和推广。 我们的目标是找到一种能够充分发挥垂直记录潜力的磁介质，并为热辅助磁记录等更高密度的方法创造机会。 为此，本工作提出了对 Co/Pd 基多层介质的研究，因为它们具有高界面诱导垂直各向异性、高矫顽力和高矩形度。 目前，工业界主要关注合金基材料，因为它们噪音较低；然而，多层似乎提供了实现极高密度磁记录和良好热稳定性的最佳机会。 传播研究经验和研究成果是这项工作的另一个重要方面。 本科生和研究生都将参与这项媒体研究，并且通过目前实施的 REU 计划，当地科学教师将有机会在暑假期间参与其中。 根据 IBM 的期望，已分配时间和预算来访问 IBM，以便 PI 更好地了解 IBM 测试结果，并向 IBM 提供有关当前进展和方向的最新信息。 我们的介质磁盘也将提供给其他公司：历史上许多公司都向 PI 索取材料，并且至少在三种情况下返回了详细的测试结果。 PI 将继续频繁拜访其他行业组织，报告本研究的结果。 所有这些都将极大地有助于技术转让。 研究 Co/Pd 多层膜的微观结构，即晶粒尺寸和晶粒之间的磁分离，对于降低噪声和实现高记录密度极其重要。拟议的工作将使用种子层和掺杂来控制微观结构，从而控制多层膜的磁性。在本研究中，将在不同的实验条件下生长具有不同氧含量程度的 0-2nm InSn 合金，以确定 Co/Pd 晶种介质的最佳晶体结构。初步研究表明，相对于交替晶种层，这将增加矫顽力，而无需高温沉积来增大晶粒。 这些多层中的掺杂剂有两个目的。 首先，迁移到晶界的掺杂剂会抑制晶粒生长，其次，它有助于确保非磁性晶界。在拟议的工作中，由于 Si 与 Co 和 Pd 的理论分离，将对其进行仔细研究。理论研究将包括实验数据的解释和新材料方法的建议。理论将在为工业合作伙伴 (IBM) 选择最佳磁盘以在旋转台上完成和测试以及解释随后的数据方面发挥特别重要的作用。 新的材料方法，或更可能的是，对所提出的材料方法进行修改以进一步提高性能也将直接源于这项理论工作。 我们将特别努力隔离硅对界面的影响，并考虑替代掺杂剂，例如Ge。

This proposal describes research and outreach involving a complementary team of experimentalist, theorist, and industry liaison. The goal is to find a magnetic medium that can reach the full potential of perpendicular recording and generate opportunity for even higher density approaches such as heat-assisted magnetic recording. For this purpose, this work proposes research on Co/Pd based multilayer media, owing to their high interface-induced perpendicular anisotropy, high coercivity and high squareness. Currently, industry focuses on alloy based materials due to their lower noise; however, the multilayers appear to offer the best chance of reaching extremely high density magnetic recording with good thermal stability. Dissemination of the research experience and the results of the research is another important aspect of this work. Both undergraduates and graduate students will be involved in this media research, and, through an REU program currently in place, local science teachers will have the opportunity to be involved during their summer break. In line with IBM expectations, time and budget allocations have been made to visit IBM both to allow the PIs to better understand IBM testing results and to give IBM updates on the current progress and directions. Disks of our media will be made available to other companies as well: historically many companies have requested materials from the PIs and, in at least three cases, returned detailed results of their tests. Frequent visits to other industrial organizations by the PIs will be continued, where they will report the results of this research. All of this should greatly aid technology transfer. Research The microstructure of Co/Pd multilayers, namely grain size and magnetic separation between the grains, is extremely important in reducing noise and achieving high recording densities. The proposed work will use seedlayers and doping to control the microstructure, and therefore the magnetic properties of the multilayers. In this study, 0-2nm of InSn alloys, with altering degrees of oxygen content will be grown under varied experimental conditions to determine the optimal crystal structure for seeding Co/Pd media. Preliminary studies suggest that this will increase coercivity, relative to alternate seed layers, without the grain-enlarging necessity of high temperature deposition. The purpose of a dopant in these multilayers is two-fold. First, a dopant that migrates to the grain boundary inhibits grain growth and, second, it helps ensure a nonmagnetic grain boundary. In the proposed work, Si will be closely examined owing to its theoretical segregation from Co and Pd. The theoretical investigations will include interpretation of experimental data and suggestion of new material approaches. Theory will play a particularly prominent role in selecting the best disks for the industrial partner (IBM) to finish and test on a spin stand, and in interpreting the ensuing data. New material approaches or, as is more likely, modification of the proposed ones to further improve performance will also stem directly from this theoretical work. Particular effort will be made to isolate the effects of Si from the interface and to consider alternate dopants such as Ge.