We report magnetic measurements on CoCrPt sputtered thin films with stackin
g fault densities ranging from 9% to 30%. These FCC-like faults mainly in t
he HCP Co-alloy grains cause an increase in regions of low coercivity, thus
promoting thermally activated magnetisation reversal. Significant differen
ces in magnetic viscosity and switching field distributions were observed.
A large increase in activation volume was observed for films with over 20%
stacking faults. The reduction in the anisotropy fields by defects allows e
xchange coupling to dominate the reversal, causing increased thermal activa
tion. (C) 2001 Elsevier Science B.V. All rights reserved.