Magnetoresistance of NiFe/Ag multilayers: modeling of the effects

Magnetoresistive Ni/sub 81/Fe/sub 19//Ag coupled multilayers have been obtained in a sputtering machine with a substrate holder rotating over the targets. The multilayers display an in-plane anisotropy perpendicular to the rotation direction. This effect leads to a sensitivity of 0.2%/Oe along the easy axis (0.6%/Oe after short appropriate annealings). A simple analytical model including bilinear, biquadratic and anisotropic energy terms gives good fits of experimental curves if thicknesses distributions and/or anisotropy distributions are taken into account.