Thermally assisted magnetic recording (TAMR) is one of the novel technologies that are employed for achieving magnetic recording densities higher than 1 Tb/in 2 . With regard to this novel technology, it has been suggested that there exists a critical head-disk interface (HDI) issue associated with the use of ultrathin liquid lubricant films on the disk surface. This problem is attributed to the fact that these films are heated to high temperatures by using laser beams in order to reduce magnetic coercivity. In this study, a fundamental research on the lubricant depletion caused due to laser heating in TAMR systems was conducted. That is, the effect of lubricant film materials on lubricant depletion was investigated. In this experimental study, four types of lubricant film materials-Zdol2000, Zdol4000, Ztetraol2000, and A20H2000-were used, and the differences in the characteristics of lubricant depletion for each tested lubricant film were investigated. The effect of the molecular weight as well as the end group of the lubricant on the lubricant depletion was discussed and clarified by analyzing the obtained experimental results. In addition, it was found that the depletion characteristics of ultrathin liquid lubricant films could be explained by using experimental results obtained from the thermogravimetric analysis for each bulk lubricant material.Index Terms-Hard disk drives, laser heating, lubricant depletion, perfluoropolyether lubricant film, thermally assisted magnetic recording systems, thermogravimetric analysis (TGA).
We report a new mastering technique that utilizes thermal decomposition of a resin; we named this technique thermal direct mastering (TDM). In this method, a multilayer consisting of a Si/ZnO/resin/glass substrate was adopted for the sample. The cover layer consisting of a Si film and a ZnO film had the following two functions: absorption of the laser beam and controlling the bumps of the resin layer. Using a deep UV (DUV) mastering system with a wavelength of 257 nm and a numerical aperture (NA) of 0.90, a monotone pattern corresponding to a 100 GB capacity (areal density: 69.5 Gbit/in.2) disc can be fabricated. In addition, a random pattern with a twofold higher linear density of a Blu-ray Disc (BD) can be fabricated. This random pattern corresponds to a 50 GB capacity (areal density: 34.8 Gbit/in.2) disc.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.