Study of Siloxane Adsorption on Hard Disk Media Surface

Area of Science:

• Tribology
• Surface Science
• Materials Science

Background:

• Siloxane contamination is a critical issue in disk drive reliability.
• Understanding siloxane adsorption mechanisms on disk surfaces is essential for preventing failures.

Purpose of the Study:

• To investigate the adsorption of siloxanes onto disk surfaces.
• To identify key disk parameters influencing siloxane adsorption.
• To elucidate the relationship between lubricant film thickness, carbon film composition, and siloxane adsorption.

Main Methods:

• Fourier-transform infrared spectroscopy (FTIR)
• X-ray photoelectron spectroscopy (XPS)
• Time-of-flight secondary ion mass spectrometry (TOF-SIMS)
• Gas chromatography-mass spectrometry (GC-MS)
• Candela Optical Surface Analyzer (OSA)

Main Results:

• Lubricant film coverage (fractional monolayer thickness) is the primary factor controlling siloxane adsorption, with adsorption decreasing as coverage increases.
• For submonolayer lubricant films, nitrogen content in the carbon underlayer significantly influences siloxane adsorption.
• Increasing nitrogen content in carbon films enhances siloxane adsorption while simultaneously increasing lubricant monolayer thickness, leading to a net increase in siloxane adsorption.

Conclusions:

• Lubricant film coverage is the most critical parameter for mitigating siloxane adsorption.
• Carbon film nitrogen content plays a dual role, affecting both lubricant film formation and siloxane adsorption.
• Optimizing carbon film composition and lubricant application is crucial for minimizing siloxane-related failures in disk drives.