One detrimental by-product of heat-assisted magnetic recording writing is the creation head contamination. Here, we present current understanding driving forces, growth mechanisms, and rates write-induced The combination an evaporation condensation model with shear forces suggests a flow lubricant on may precipitate contamination observed to grow in head-media gap until it contacts media surface, at which point additional material pickup mechanism can be activated. Evidence contact-induced...

Adsorption of CH3OH on Cu2O(111), ZnO(0001), and ZnO(1010) has been investigated with XPS, NEXAFS, variable-energy photoelectron spectroscopy (PES), SCF-Xα Scattered Wave (SW) molecular orbital calculations. At high coverage (≥25.0L), is adsorbed as multilayers all three surfaces. low temperatures (140 K) (0−0.6L), deprotonated to form chemisorbed methoxide the surfaces investigated. Under these conditions C1s XPS peak positions are 289.5, 290.2, 290.2 eV below vacuum level, respectively....

An optical pump-probe set-up that allowed short dwell time ( ~ 500 μs) heating with a high-temperature ramp rate 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> K/s) was used to detect the magnetization change in heat assisted magnetic recording (HAMR) media. The temperature of media monitored by observing Kerr signal. pump power at zero determination needed attain Curie (the determined magnetometer before experiments). HAMR then...

An understanding of the factors influencing thermal stability ultrathin carbon overcoats (COCs) is crucial for their application in heat-assisted magnetic recording (HAMR) at densities ≥ 1 Tb/in2. Two types non-hydrogenated (∼1.5 nm) COCs were investigated after being subjected to laser-induced localized heating (at temperatures > 700 K) as envisaged HAMR. Filtered cathodic vacuum arc (FCVA)-processed with tuned C+ ion energies 350 eV followed by 90 provides significantly higher sp3 C–C...

We have identified conditions in which the atomic force microscope can be used to stretch a meniscus of perfluoropolyether (PFPE) lubricant pinned between an AFM tip and nanometer-thick PFPE film obtain disjoining pressure film. Under quasi-equilibrium conditions, chemical potential equated that stretched meniscus. A theory is presented provides complete description capillary Fits force-extension curves yield effective curvature and, by extension, underlying collected at varying thicknesses...

Lubricant accumulation was found on the media surface instant when laser is turned OFF during heat-assisted magnetic recording write operations. By changing cycles, ON/OFF duration, media, and head temperatures, we find that this lubricant related to change in head-media temperatures. The observed deposition process restricted a short time window (1-2 μs) after OFF. An equilibrium model of thermal displacement due evaporation condensation processes presented used discuss effect temperature...

Heat-assisted magnetic recording involves the transfer of energy to medium via optical means. To enable high areal density, recorded track must be smaller than diffraction limit focused light, which is accomplished by using a near-field transducer (NFT) with corner or peg small dimension. Energy such effect, and therefore highly sensitive spacing between NFT medium. Since has some surface roughness, there will variation in NFT-to-medium this impact amount transferred from NFT. We model...

Atomic force microscopy (AFM) was used to measure the disjoining pressures of perfluoropolyether lubricant films (0.8-4.3 nm Fomblin Z03) on both silicon wafers and hard drive disks coated with a diamondlike carbon overcoat. Differences in pressure between two systems were expected be due variations strength van der Waals interactions. Lifshitz theory calculations suggest that this substrate switch will lead relatively small changes as compared more pronounced effects reported chemistry. We...

Lifshitz theory of van der Waals interactions is applied to the geometry and materials head-disk interface (HDI). A simplified two-substrate model with intervening air gap used illustrate effects retardation. The calculation Hamaker functions for increasingly complex layered structures then presented importance multilayered nature HDI on (vdW) interaction. full Lifshitz-multilayer compared approximations vdW force relative errors are displayed. results indicate necessity performing a...

The dispersive and polar components of surface energy, which are typically obtained from the two-liquid geometric method through contact angle measurement, have been extensively used to study interfacial properties perfluoropolyether (PFPE) lubricated media in hard disk drive industry. In this paper, an alternative approach, Lifshitz-van der Waals Lewis acid-base (LW/AB) theory, provides additional information on nature lubricant/overcoat interaction, has applied energy PFPE-coated media....

The disjoining pressure of lubricant in the magnetic storage device head-disk interface (HDI) was obtained using Lifshitz theory [Sov. Phys. JETP 2, 73 (1956)] and multilayer film stack model. For this purpose normal-air-gap-centered calculation replaced by lubricant-layer-centered system. In air-centered system attractive force between head media found to increase as layer thinned. By switching lubricant-centered a thin HDI be negative at small head-to-media separation. equating free with...

A multilayer Lifshitz calculation of van der Waals interactions at the magnetic storage head–disk interface is presented. The Hamaker function for model film stacks that incorporate different media overcoat materials obtained. These functions allow comparison interfacial forces when coated with diamondlike carbon, and without inclusion hydrogen annealing, SiNx films. significant difference, ∼30%, in magnitude force overcoats calculated.

The carbon overcoat (COC) on heat-assisted magnetic recording (HAMR) media was deposited at increasing temperature. optical extinction (k) of this measured with ellipsometry and found to increase temperature from 0.2 0.9 over the range 220 °C 360 °C. Raman spectroscopy these COC surfaces had an G-peak position decreasing width along I(D)/I(G). An sp <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ring/chain aromatic cluster size gap were...

A pump-probe experimental technique that incorporated a 527nm wavelength pump laser and 476nm probe was applied to magnetic storage disk having layer comprised of FePt alloy coated with hydrogenated carbon overcoat (COC). The power systematically increased while sweeping the field an electromagnet observe temperature dependent magnetization, which is proportional change in polarization reflected beam. In this way required heat media Curie (Tc) determined, determined from separate...

Lifshitz theory has been used to calculate the van der Waals (vdW) force between a magnetic storage read-write head over both lubricated glass disk and disk. These forces were then incorporated into an air-bearing simulation that calculates flying height of slider as function revolutions per minute (rpm) for types media. A sharp decrease in was calculated at approximately 1950 rpm, whereas similar is observed 150 rpm slower differences ascribed significantly larger vdW acting media, when...

In order to increase recording density for magnetic systems, the fly height of slider, as part head-media spacing, has remain ultra-low through proper air-bearing designs. At these heights, presence interfacial forces, such van der Waals (vdW) force, can significantly affect flying characteristics. this paper, one design been studied at heights with a proprietary simulation code, where Lifshitz-theory-based fully retarded vdW force model was applied on multilayered head-disk interface (HDI),...