Abstract

Liquid lubricants reduce friction and wear at the recording surface of rigid magnetic disks. Loss of this lubricant can come from centrifugal effects, from evaporation, and from periodic contacts of the recording head slider rails with the lubed disk surface. Magnetic disk lubricant levels have been quantified by ESCA, by IR spectroscopy, and by ellipsometry. However, ellipsometry techniques on multilayered thinly lubed magnetic disks are complicated by multi-angle measurements and numerical calculations that are difficult to apply, while ESCA requires exposure of the lube to undesirable high-vacuum conditions. Infrared spectroscopy is easy to apply, avoids vacuum concerns and, with a grazing angle approach, has very good sensitivity. Also desirable is the capability of submillimeter spatial resolution. A device that meets these requirements is a Grazing Angle Microscopy (GAM) for infrared spectroscopy. Aside from providing magnification to analyze very small spots, a GAM with 65 to 80° incident illumination also provides the enhanced sensitivity to very thin films that ordinary IR microscopes (with normal incident illumination) lack. An example of this sensitivity is shown in Fig. 1, where the GAM measured absorbance for a 0.5 × 0.2 mm spot is distinguishable below 10 angstroms (1 nm) of perfluoropolyether lube thickness. In this study a GAM was used to quantify the polyether lube depletion on a developmental thin-film disk within the contact points of the recording head slider rails used in a routine wear test (i.e., oscillatory wear tester).

Determining the optical constants of read-write sliders during flying-height testing

Peter de Groot, Ara Dergevorkian, Tod Erickson, and Russell Pavlat
Appl. Opt. 37(22) 5116-5125 (1998)

Optical properties of alumina titanium carbide sliders used in rigid disk drives

Peter de Groot
Appl. Opt. 37(28) 6654-6663 (1998)

Optical property study of FePt-C nanocomposite thin film for heat-assisted magnetic recording

Z. H. Cen, B. X. Xu, J. F. Hu, J. M. Li, K. M. Cher, Y. T. Toh, K. D. Ye, and J. Zhang
Opt. Express 21(8) 9906-9914 (2013)

High-density–speed optical near-field recording–reading with a pyramidal silicon probe on a contact slider

Takashi Yatsui, Motonobu Kourogi, Kazuo Tsutsui, Motoichi Ohtsu, and Jun-ichi Takahashi
Opt. Lett. 25(17) 1279-1281 (2000)

High storage density optical disks using pit-edge recording on PbTeSe thin film

Atsushi Saito, Takeshi Maeda, Hisataka Sugiyama, and Yoshito Tsunoda
Appl. Opt. 27(20) 4274-4278 (1988)