Viscoelasticity of PFPE lubricant films on magnetic disk surface measured by optical-fiber-based nanorheometry

We measured viscoelastic properties of molecularly thin lubricant films on magnetic disk surface under the shearing motion. As a lubricant, Fomblin Zdol4000 was used. Thickness of the film was around 2 nm. Our results indicate that the chemical adsorption of lubricant molecules to the disk surface strongly enhanced the elasticity of the films.