We investigate the effect of Al doping on the magnetic properties of the CoFeB alloy. Comparative measurements of the saturation magnetization, the Gilbert damping parameter α, and the exchange constant as a function of the annealing temperature for CoFeB and CoFeAlB thin films are presented. Our results reveal a strong reduction of the magnetization for CoFeAlB in comparison to CoFeB. If the prepared CoFeAlB films are amorphous, the damping parameter α is unaffected by the Al doping in comparison to the CoFeB alloy. In contrast, in the case of a crystalline CoFeAlB film, α is found to be reduced. Furthermore, the x-ray characterization and the evolution of the exchange constant with the annealing temperature indicate a similar crystallization process in both alloys. The data prove that CoFeAlB fulfills the requirements to be considered an attractive candidate for spin torque switching purposes and a reduction of the switching current in comparison with CoFeB is expected.
ASJC Scopus subject areas
- Physics and Astronomy(all)