Abstract: A magnetic disk having improved tribological characteristics in the data zone of the disk surface while retaining a low sliding stiction in the landing zone is disclosed. It contains the conventional elements of a substrate, a magnetic recording layer, a protective overcoat, and a lubricant layer on the protective overcoat. However, the lubricant layer is UV irradiated under a photo mask to cause a radially inner zone and a radially outer zone. The photo mask is designed so that the radially outer zone of the lubricant layer has a ratio of bonded/unbonded lubricant molecules greater than that in the radially inner zone. The reduced proportion of mobile lubricant molecules in the data zone prevents the lubricant molecules from being collected by the magnetic head. On the other hand, a large proportion of the lubricant molecules in the landing zone remained mobile. This allowed the sliding stiction in the landing zone to stay at the desiredly low value.

Abstract: A magnetic recording medium for use in making high-density computer hard disks. It contains: (a) an aluminum or Ni/P substrate; (b) a chromium underlayer on the substrate; (c) a four-component magnetic recording layer on the underlayer; and (d) a carbon protective layer on the magnetic recording layer. The magnetic recording layer comprises 66-78 atom percent of cobalt, 12-16 atom percent of chromium, 6-10 atom percent of nickel, and 4-8 atom percent of tantalum. The CoCrTiTa four-component exhibits a high coercivity (greater than 2,800 Oe), which results in many improved qualities, including increased recording density, reduced noise, improved off-track capability (OTC), and reduced on-track error rate (OTER). It also also allows the sputtering process to be conducted at a substantially lowered temperature.

Abstract: A method for predicting total bump height reduction from volume wear rate data for a laser textured magnetic disk. In this method, a bump topography function, r(h), is first established by which the bump half-width, r, is expressed as a function of bump depth, h. Then the bump height depth after first revolution, h.sub.1, is calculated according to the following equation: ##EQU1## Based on the observation of constant wear volume per cycle, the bump height depth after each subsequent revolution, h.sub.i, i=2 . . . N, is calculated according to the following equation: ##EQU2## The so-calculated h.sub.N is the total bump height reduction after the Nth revolution.

Abstract: A wet etching method for making calibration bump disks for use in providing quality control of production run magnetic hard disks is disclosed. It includes the steps of: (a) coating a layer of bump material on a substrate; (b) coating a photoresist layer on the layer of bump material; (c) exposing the photoresist layer to a light source under a photomask; (d) developing the photoresist layer using a developer solution to form an undeveloped photoresist layer; (e) etching the substrate containing the layer of bump material and the undeveloped photoresist layer to remove portions of the layer of bump material not covered by the undeveloped photoresist layer; and (f) stripping the undeveloped photoresist layer to leave at least a bump on the substrate which was originally covered by the undeveloped photoresist layer. The wet etching method eliminates many of the problems observed from the conventional metal mask method, including the elimination of the convex-shaped bump surface.

Abstract: A thin-film magnetic recording media is prepared which contains a carbon overcoat sputtered on a magnetic recording layer. The carbon overcoat is sputtered on the magnetic recording layer using a sputtering process which is conducted in a sputtering chamber having an inert gas and a mixture of nitrogen gas and hydrogen gas, wherein said nitrogen gas and hydrogen gas are provided at a mole ratio of nitrogen/hydrogen between about 0.5 and about 1. The hydrogen and nitrogen doped amorphous carbon overcoat exhibits excellent mechanical properties and tribological performance.