The thermal stability of the magnetic properties of CoCr thin films for per
pendicular recording media is analyzed with measurement of the dependence o
f the coercivity on the applied field sweep rate, in films with different t
hickness, Cr content, and presence or absence of a soft FeNi underlayer, Th
e results are discussed on the basis of the evolution of the magnetization
reversal mode, owing to the different microscopic structure and magnetic or
der of the films, which indicates weaker thermal stability of the magnetic
properties in films with the smallest thickness, lowest Cr content, and the
presence of the FeNi underlayer.