Magnetic viscosity effects in Co-alloy thin films with stacking faults

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.