STRUCTURE AND MAGNETISM OF FE SI MULTILAYERS GROWN BY ION-BEAM SPUTTERING/

Ion-beam sputtering has been used to prepare Fe/Si multilayers on a va riety of substrates and over a wide range of temperatures. Small-angle x-ray-diffraction and transmission electron microscopy experiments sh ow that the layers are heavily intermixed although a composition gradi ent is maintained. When the spacer layer is an amorphous iron silicide , the magnetic properties of the multilayers are similar to those of b ulk Fe. When the spacer layer is a crystalline silicide with the B2 or DO3 structure, the multilayers show antiferromagnetic interlayer coup ling like that observed in ferromagnet/paramagnet multilayers such as Fe/Cr and Co/Cu. Depending on the substrate type and the growth temper ature, the multilayers grow in either the (011) or (001) texture. The occurrence of the antiferromagnetic interlayer coupling is dependent o n the crystallinity of the iron and iron silicide layers, but does not seem to be strongly affected by the perfection of the layering or the orientation of the film. Since the B2- and DO3-structure FexSi1-x com pounds are known to be metallic, antiferromagnetic interlayer coupling in Fe/Si multilayers probably originates from the same quantum-well a nd Fermi surface effects as in Fe/Cr and Co/Cu multilayers.