Influence of stress on nucleation field of CoCrPt perpendicular media

The influence of stress on the nucleation field was investigated for CoCrPt perpendicular media grown on a Ta/Hf buffer layer. The nucleation field increased to −1.5 kOe (second quadrant) following postdeposition annealing of a sample at 232 °C in air for 1 h. The residual in-plane stress for the annealed film was tensile, and in-plane x-ray diffraction showed that the a0 lattice parameter increased with increasing annealing time. It is believed that the change in stress was due to surface oxidation of the CoCrPt film. The increased stress anisotropy perpendicular to the plane of the film resulted in the increased nucleation field.