Analyses of stacking fault density in Co-alloy thin films by high-resolution transmission electron microscopy

The density of stacking faults in Co-alloy thin films has been analyzed to study the effect of the fault density on the magnetic properties. The stacking fault density is measured using high-resolution transmission electron microscopy with a Ta or Pt content of 2-8 at%. The average number of the faults which exist in one Co unit cell is 0.1-0.2. The stacking fault density increases with the increase of Ta or Pt content. The fault densities for the CoCrPt films are 10-30% higher than those of the CoCrTa films. Substrate biasing slightly increases the stacking fault density. The influence of the crystal perfection on the anisotropy field seems small compared to other effects such as an in-plane strain.