Properties of transition metal-metalloid ferromagnetic thin films

It has been possible to deposit by r.f. sputtering amorphous ferromagnetic thin films for metalloid content from 0 to 40 atom percent; the properties of these films are comparable to those of bulk ribbons obtained by rapid quenching from the melt. FeSi and FeB sputtered thin films are amorphous for alloys containing respectively 26 and 16 atom per cent metalloid, and films are still magnetic for metalloid content of 40 atom per cent. Their resistivity, 100-200 μΩ-cm, is characteristic of most amorphous metallic alloys. The magnetostriction of these alloys is very high and positive and decreases with increasing silicon or boron concentration. The as-deposited films show perpendicular anisotropy, but soft magnetic properties have been obtained after a short annealing procedure at temperature below the crystallization temperature.