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Here we demonstrate a new approach to bring the disk drive recording head close to the disk media, while achieving tight control of the final head-media separation. The slider in this approach has a miniature Wear-In-Pad (WIP) at its trailing edge, encapsulating the read/write elements. As the slider flies over the disk, the slider overcoat and head recession are quickly worn off, resulting in the bottom of read and write elements clearing the disk roughness by only a few nanometers. We show that the Wear-In-Pad is a viable way to achieve the sub 7 nm head-media separations believed to he necessary for Tb/[in.sup.2] recording. Index Terms--Disk drive tribology, head-disk interface, magnetic spacing, wear.

We demonstrated recording performance at greater than 10 Gb/[in.sup.2] with data rates up to 25 MB/s, using a single combined write and read head (Merge Notched head).

Nanoindentation data are presented for three different but interrelated components of the thin film disk magnetic recording system - the air bearing slider/recording head, the disk substrate, and the sputter deposited thin film disk recording medium. Hardness traces across the slider trailing edge demonstrate the hardness of the NiFe, sputtered [Al.sub.2][O.sub.3], and the ceramic [Al.sub.2][O.sub.3]/TiC are 8, 10 and 24-40 GPa, respectively. Lapping under non-optimum, aggressive conditions can lead to significant recession in these components which is directly related to their hardness. The hardness and modulus have been measured for a number of alternate substrate materials ranging from AIMg/NiP to glass and glass ceramic. The ability of these substrates to resist damage from slider shock forces is presented and generally increases with substrate hardness, although other criteria (fracture toughness and plasticity initiation) are required to rationalize all the data. Finally, hardness and modulus of carbon overcoat films are presented which have been sputtered under various conditions. The process variations lead to variations in hardness, the hardness/modulus (H/E) parameter, and tribological performance in slider/disk testing. The applicability of these mechanical property parameters to the wear degradation is discussed.

Vapor corrosion inhibitor can improve the reliability of heads and disks in a hard disk drive by forming a protective film over exposed metal. Diffusion channels from a source and to a drain are designed to control the steady state relative partial pressure of the desirable species below saturation. Extended accelerated life tests and repeated condensing humidity cycle tests demonstrate the improved reliability. Index Terms--Corrosion, disks, head, reliability.

As the magnetic recording density increases toward hundreds of Gb/[in.sup.2], both the magnetic spacing and head-disk clearance decrease to Index Terms--Air bearing surface, flyability, flying height, hard disk drive, takeoff height, tangential curvature.

The adoption of dual zone texturing on magnetic disks allows the flying height of the head to be reduced over the data zone compared to a fully textured disk. Laser texture offers a technique for precise topography control and the placement of the landing zone. In this study the effects of the clearance between the head and the disk, and the presence or absence of overcoat on the air bearing surface on contact start-stop performance are evaluated. The wear mechanism of the laser bump by the head was investigated with in-situ monitors and followed by surface analysis. Acceptable durability and stiction performance for contact start-stop operation is feasible with a few nm of clearance.

The incorporation of a limited amount of hydrogen in the amorphous carbon (a-C:H) overcoat improves the CSS durability of thin film media lubricated with perfluoropolyether (PFPE). A mechanism is proposed to explain this phenomenon. With increasing H content in C, the likely bonding sites for the lubricant such us the carboxyl end groups and dangling bonds decrease in the carbon films. Mobility of the lubricant measured by two different techniques was found to increase with increasing H. The improved interface durability is attributed to the enhanced lubricant mobility on hydrogenated carbon.

As magnetic recording areal density increases the mechanical spacing between the head and the disk continues to shrink. Head protrusion, induced by write current heating of the coil and yoke during recording at operating temperature, may interfere with the disk. In this work, we have measured the head temperatures as a function of write current, frequency and flying conditions. The rise in coil temperature for a flying head was found to be much less than a head on the load/unload ramp. The measured temperature coefficient was consistent with the simulation. The amount of head protrusion was measured as a function of the write current. The head-disk interaction of the interface after 100 000 write current bursts resulted in alumina wear. Some of the effects of head protrusion on the interface reliability are discussed. Index Terms--Head-disk interface, head temperature and protrusion, magnetic recording.

To achieve an areal density approaching 50 Gb/[in..sup.2] for the magnetic storage of data in hard disk drives requires reduced mechanical and magnetic spacing. Off-track jitter caused by airflow or contact can cause track misregistration on the order of 20-70 nm which may be excessive for adequate servo performance. The magnetic signal can be used to identify both the vertical spacing modulation due to the air bearing modes and off-track jitter due to suspension modes with nanometer resolution. We find that the off-track jitter in the flying regime is driven by airflow and is a strong function of the disk velocity and the suspension type. In the contact regime, the vertical spacing modulation and off-track jitter increase due to contact. Using a laser Doppler vibrometer we identified the leading contribution to the off-track jitter to be primarily the first torsional mode (TI) and to a lesser extent the first bending mode (BI) of the suspension. [DOI: 10.1115/1.1308037]

As the magnetic recording areal density approaches 10 Gb/[in.sup.2], the mechanical spacing between the head and the disk is expected to reduce rapidly below 20 nm. This leads to an increase of head-disk interaction which may induce an unacceptable level of interfacial wear. in this study experimental air bearing sliders were designed and fabricated to fly in close proximity or substantial contact with the disk. The durability of the interface decreased with decreasing mechanical clearance. The amount of head and disk wear was determined. The metrology and some of the challenges in maintaining a functional interface are presented. Index terms--head-disk interface, contact recording, tribology.