Surface and lubricant/overcoat interface properties of the rigid disks after corrosion

The surface and perfluoropolyether (PFPE) lubricant/overcoat properties of magnetic hard disks after corrosion stressed at a temperature of 80 degrees C and an 80% relative humidity are studied by time-of-flight secondary ion mass spectrometry. The corrosion stress leads to selective migration of cobalt from the magnetic layer which is dependent on disk overcoat composition and structure. The corrosion also results in evaporation and degradation of the PFPE lubricant.