Effects of vacuum ultraviolet irradiation to lubricant layer on hard-disk media

Summary form only given. Adhesion between a lubricant and DLC (diamond-like carbon) used as a protective layer in magnetic recording media improves HDI (head disk interface) characteristics. Therefore, magnetic recording media coated with lubricant are treated with heat or ultraviolet (UV) to increase the thickness of the bonded layer on the DLC and to optimize friction, durability, and other characteristics of the media. Because there are many different photoreactions and photo-induced reactions are known, we believe that this UV treatment is an attractive technique to improve the characteristics of the media. Usually, UV treatment is carried out by using a low-pressure mercury lamp, which irradiates at a wavelength of 185 and 254 nm with an intensity ratio of one to five. Our research interest includes investigating applications of short-wavelength irradiation because it can produce more photoelectrons increasing the thickness of the bonded lubricant layer. To examine and determine the potential of ultraviolet treatment, we investigated the effects of 172 nm irradiation in the vacuum ultraviolet region.