Oxygen effects on magnetic properties during annealing of sputtered Co-Gd-Mo films

Two sets of amorphous Co-Gd-Mo films with compensation temperatures below and above room temperature were annealed in various atmospheres. The changes in the net magnetization, the perpendicular anisotropy field and the uniaxial anisotropy constant were measured at room temperature after the annealing procedure. All the observed effects could be consistently explained by prefered oxidation of the Gd-“sublattice” atoms. Proper annealing allows one to obtain films with magnetic constants desired for device applications.