FE STRUCTURAL AND MAGNETIC PHASES IN FE NI81FE19(001) MULTILAYERS/

The structure of epitaxially sputtered single-crystalline Fe/Ni81Fe19( 001) multilayers was studied using X-ray diffraction. As the thickness of the Fe layers is increased the structure of the Fe layers changes from vertically expanded fcc (001) to relaxed fcc (001), and finally, to bcc (011), thus identically replicating the structural behavior fou nd in thin Fe films on Cu (001) single crystals. Corresponding to the structural transitions of the Fe layers are changes in the magnetic pr operties. The relaxed fee phase contains non-magnetic Fe, which can le ad to antiferromagnetic coupling of the Ni81Fe19 layers across the Fe layers.