MAGNETIC-PROPERTIES OF ION-BEAM SPUTTER-DEPOSITED NIFE ULTRATHIN FILMS

Studies have been made of the magnetic properties of NiFe ultrathin fi lms 15-100 Angstrom thick. The NiFe films were deposited on Cu, Ti, an d Ta underlayers by an ion-beam sputtering method. In the NiFe films d eposited on the Cu layers, the saturation magnetization shows Little c hange with thickness down to 60 Angstrom, but below this it shows a gr adual decrease with decreasing thickness. The coercivity in the hard a xis is almost unaltered with the film thickness, whereas the coercivit y in the easy axis and the anisotropy field decrease with decreasing f ilm thickness. Both values greatly decrease below 30 Angstrom, Thickne ss dependence of the induced uniaxial anisotropy constant and the dire ct-current permeability were obtained from these parameters. Remarkabl e decreases of these parameters were observed in the films on the Ti a nd Ta layers likely owing to the formation of fine islands. Magnetic p roperties and giant magnetoresistance in multilayers are discussed on the basis of the present experimental results. (C) 1995 American Vacuu m Society.