Decomposition of perfluoropolyether lubricant picked up on actual air bearing surface in heat-assisted magnetic recording

The thermal decomposition of D-4OH lubricant thin film on an actual air-bearing surface under heating conditions was investigated using time-of-flight secondary ion mass spectroscopy (TOF-SIMS). The substrates used in this experiment are those of actual magnetic head sliders with diamond-like carbon (DLC) thin-film coatings. Two kinds of surfaces were prepared; an undisturbed DLC thin-film surface and an AhO3 surface exposed by sputtering of the DLC thin film. Comparison of the changes in the positive mass spectra due to heating confirmed that thermal decomposition of the D-4OH lubricant thin-film occurred and that it could be accelerated by the catalysis of Al2O3 at heating temperatures below 150°C. This is despite the fact that the D-4OH lubricant thin-film on the undisturbed DLC thin-film surface did not decompose.