Adhesion Properties of Monolayer Lubricant Films Coated on Magnetic Disk Surfaces: Contributions of Mobile and Bonded Molecules

• Published in: IEEE transactions on magnetics Vol. 48; no. 11; pp. 4269 - 4272
• Main Authors: Lu, Renguo, Zhang, Hedong, Itakura, Masashi, Fukuzawa, Kenji, Itoh, Shintaro
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.11.2012; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adhesion; Adhesives; bonding ratio; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Force; Force measurement; Lubricants; Magnetism; Materials science; Mobile communication; monolayer lubricant film; Other topics in materials science; Physics; Probes; surface coverage; bonding ratio; Lubricants; Monolayers; monolayer lubricant film; Disks; surface coverage; Adhesion; Magnetic properties
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2012.2196983

Monolayer lubricant films on magnetic disk surfaces consist of bonded and mobile molecules whose different adsorption states may result in different adhesion properties, which directly impact the stability of ultra-low flying head-disk interfaces. By measuring the adhesion force and the surface coverage as a function of bonding ratio, we investigated the contributions of the bonded and mobile molecules to the adhesion of monolayer perfluoropolyether Zdol4000 and Z03 films. The experimental results, which agree with our theoretical results, indicate that bonded lubricant molecules decrease adhesion by increasing the surface coverage, whereas the ability of mobile lubricant molecules to reduce adhesion depends on their adsorption strength with the substrate. Mobile molecules with polar end groups tend to adsorb strongly on a disk, thereby increasing the surface coverage and decreasing the adhesion force.