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

GOALI：用于垂直磁记录介质的 ITO 种子层上的硅掺杂 Co/Pd 多层

• 批准号: 0300209
• 负责人: Bethanie Stadler
• 金额: $ 30万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-15 至 2007-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0300209&HistoricalAwards=false
• 关键词: GOALI; Si; doped; Co; Pd

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.

该提案描述了一个由实验学家、理论家和行业联络人组成的互补团队的研究和推广。目标是找到一种磁性介质，可以充分发挥垂直记录的潜力，并为更高密度的方法（如热辅助磁记录）创造机会。为此，本工作提出了基于Co/Pd的多层介质的研究，因为它们具有高界面诱导的垂直各向异性，高矫顽力和高方形度。目前，工业关注的是合金基材料，因为它们的噪音更低；然而，多层似乎提供了达到极高密度磁记录的最佳机会，并具有良好的热稳定性。研究经验和研究结果的传播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，通过REU目前的一个项目，当地的科学教师将有机会在暑假期间参与其中。按照IBM的期望，已经为访问IBM分配了时间和预算，以便pi能够更好地理解IBM的测试结果，并向IBM提供有关当前进展和方向的最新信息。我们媒体的磁盘也将提供给其他公司：从历史上看，许多公司都要求pi提供材料，至少在三种情况下，他们返回了详细的测试结果。pi将继续经常访问其他工业组织，并在那里报告这项研究的结果。所有这些都将大大有助于技术转让。Co/Pd多层膜的微观结构，即晶粒尺寸和晶粒间的磁分离，对于降低噪声和实现高记录密度至关重要。提出的工作将使用种子层和掺杂来控制微结构，从而控制多层材料的磁性。在本研究中，将在不同的实验条件下生长0-2nm的不同氧含量的InSn合金，以确定播种Co/Pd介质的最佳晶体结构。初步研究表明，这将增加矫顽力，相对于交替种子层，没有晶粒扩大的高温沉积的必要性。掺杂剂在这些多层材料中的作用有两个方面。首先，迁移到晶界的掺杂剂抑制了晶粒的生长，其次，它有助于确保非磁性晶界。在提议的工作中，由于理论上硅与Co和Pd的分离，将对其进行仔细研究。理论研究将包括对实验数据的解释和对新材料方法的建议。理论将在为工业合作伙伴（IBM）选择最佳磁盘以在旋转支架上完成和测试以及解释随后的数据方面发挥特别突出的作用。新的材料方法，或者更有可能的是，修改已提出的材料以进一步提高性能，也将直接源于这项理论工作。将特别努力从界面中分离出Si的影响，并考虑诸如Ge之类的替代掺杂剂。