Vapor Lubrication of Magnetic Data Storage Media

提出了一种研究计划，该计划解决了在磁性数据存储介质的润滑中出现的许多关键摩擦学问题。随着存储在硬盘表面上的数据面密度的增加，读写头和磁盘表面之间的间隙必须减小。该间隙目前为20 nm，预测为了以1Tbit/in^2的密度存储数据，该间隙必须减小到5 nm。在间歇高速磁头-磁盘接触期间，磁盘表面上的液体润滑剂薄膜(1-2 nm)对于保护磁盘表面至关重要。随着磁头和磁盘之间的间隙减小，对这种润滑膜的性能的要求增加，并且对其特性的公差变得越来越紧。拟议的研究计划探索了一些必须了解的基本科学问题，以便开发一种在高度可控的真空条件下将润滑剂应用于磁盘表面的新的气相方法。拟议的研究计划是一个产学研合作项目，将发展对沉积在新溅射的非晶态碳涂层上的润滑膜性质的物理化学理解，这些涂层覆盖在介质表面。这项研究是由一种新建造的设备实现的，该设备模拟了气相沉积过程，同时还允许研究气相沉积在非晶碳(a-C)涂层上的润滑膜的表面性质和表面化学。将研究新溅射的a-C涂层的氧化，以确定氧化动力学，并确定暴露在O2和H2O中在a-C表面产生的一些物种。为了了解全氟聚烷基醚(PFPE)润滑剂与新鲜和氧化的a-C表面的结合情况，将研究氟化醚和醇在新鲜和氧化的a-C膜上的吸附。最后，将研究PFPE润滑剂本身在新鲜和氧化的A-C表面上的表面化学和表面性质。需要了解PFPE润滑剂在新沉积的a-C膜和暴露在空气中的a-C膜上的差异，以帮助开发气相润滑工艺并将其过渡到实践中。拟议项目的影响相当广泛，超出了对作为新兴蒸汽润滑技术基础的科学的基本理解的发展。拟议的研究将对技术本身产生直接影响，而PI与数据存储行业的联系将使工作成果直接传播给数据存储行业的科学家和工程师，他们将把这项技术转移到商业部门。这项技术的快速发展将有助于美国数据存储行业在竞争极其激烈的行业中保持领先地位。PI、共同PI和学生每季度与信息存储产业联盟(INSIC)的成员和卡内基梅隆大学数据存储系统中心(DSSC)的成员会面。这些会议是传播研究成果和行业反馈的场所，同时也为教育、培训和让学生了解数据存储的发展提供了极好的机会。

A research program is proposed that addresses a number of critical tribological issues that arise in the lubrication of magnetic data storage media. As the areal density of data stored on hard disk surfaces increases, the gap between the read-write head and the disk surface must decrease. The gap is currently 20 nm and predictions are that in order to store data at densities of 1 Tbit/in^2 the gap will have to be reduced to 5 nm. A thin film (1 - 2 nm) of liquid lubricant on the disk surface is critical for protection of the disk surface during intermittent high speed head-disk contacts. As the gap between the head and the disk decreases, the demands on the performance of this lubricant film increase and the tolerances on its characteristics grow tighter and tighter. The proposed research program explores some of the fundamental scientific issues that must be understood in order to develop a new vapor phase method for applying lubricant to the disk surface under highly controlled vacuum conditions. The proposed research program is an industry-university collaboration that will develop the physico-chemical understanding of the properties of lubricant films deposited on the freshly sputtered amorphous carbon overcoats that cover the media surface. This research is made possible by a newly built apparatus that emulates the vapor deposition process while also allowing study of the surface properties and the surface chemistry of lubricant films vapor deposited onto amorphous carbon (a-C) overcoats. Oxidation of freshly sputtered a-C overcoats will be studied in order to determine the kinetics of oxidation and to identify some of the species produced on the a-C surface during exposure to O2 and H2O. The adsorption of fluorinated ethers and alcohols with fresh and oxidized a-C films will be studied in order to understand the bonding of perfluoropolyalkylether (PFPE) lubricants with fresh and oxidized a-C surfaces. Finally, the surface chemistry and surface properties of PFPE lubricants themselves will be studied on the surfaces of fresh and oxidized a-C surfaces. Understanding the differences between PFPE lubricants on the freshly deposited a-C films and air-exposed a-C films is needed in order to help the development of the vapor lubrication process and its transition into practice. The impact of the proposed project extends quite broadly beyond the development of a fundamental understanding of the science underlying the emerging technology of vapor lubrication. The proposed research will have a direct impact on the technology itself and the PI's connections with the data storage industry will enable the results of the work to be directly disseminated to the scientists and engineers within the data storage industry who will transfer this technology into the commercial sector. The rapid development of this technology will help the U.S. data storage industry to maintain its leadership position in an extremely competitive sector. The PI, the co-PIs and students meet quarterly with the members of the Information Storage Industries Consortium (INSIC) and with the members of Carnegie Mellon's Data Storage Systems Center (DSSC). These meetings serve as venues for dissemination of research results and for feedback from industry while also providing an excellent opportunity for educating, training, and exposing students to developments in data storage.