ELECTRODEPOSITION OF ULTRATHIN MAGNETIC-FILMS OF FE AND CO

We electrodeposited ultrathin magnetic Fe and Co films on Cu(001) crys tals from an aqueous 0.3 M Na2SO4/(Fe or Co)SO4 electrolyte in a newly developed electrochemical cell. A deposition procedure of Fe from an organic electrolyte of propylene carbonate has been additionally devel oped to prevent the significant H-2 evolution during the Fe deposition from an aqueous electrolyte. Fe films of more than 8 monolayer (ML) t hickness show the easy magnetization axis in plane. The saturation mag netization correlates linearly with the film thickness. In the thickne ss range between 2 and 8 ML, the easy magnetization axis is in the [00 1] direction. No magnetization is observed in films with thickness of less than 2 ML. Co films show in-plane magnetization with square hyste resis loops and a linear correlation of the saturation magnetization a nd film thickness above 2 ML. The magnetization vanishes at coverages of less than 1.5 ML as known from molecular beam epitaxy grown films. The coercive field of the Co films varies approximately linearly from 0.9 mT at 2.5 ML to 25 mT at 51 ML film thickness. (C) 1997 American I nstitute of Physics.