Thermal stability of Fomblin Z and Fomblin Zdol thin films on amorphous hydrogenated carbon

Thermal desorption spectroscopy has been used to monitor the decomposition kinetics of Fomblin Zdol and Fomblin Z lubricant films adsorbed to the amorphous carbon overcoats of hard disk media. Comparisons have been made between Fomblin Z and Zdol with vastly different molecular weights (MW = 4000 and 50000), and films of Fomblin Z with different thickness (20 and 60 Angstrom). Several species have been observed desorbing from the surface during heating. In all cases decomposition occurs over roughly the same temperature range of 600-750 K. This suggests that the desorption process is the result of decomposition and that the end groups of the Fomblin lubricants are not involved in determining the kinetics of this decomposition reaction. The activation barrier to the decomposition process has been estimated at 114 +/- 6 kJ/mol.