‘‘Field-dependent interface resistance’’ of Ag/Co multilayers

Abstract

For Ag thicknesses large enough to magnetically decouple the Co layers, the resistances in magnetic field of a series of Ag/Co multilayers with the current flowing perpendicular to the layer plane are consistent with a simple series summation of resistances due to the Ag and Co layers plus an ‘‘interface resistance’’, ${\mathit{R}}_{\mathrm{Ag}\mathrm{-}\mathrm{Co}}$(H), that depends upon the relative orientations of the magnetizations in neighboring ferromagnetic layers in different magnetic fields, H. The resulting Co resistivity is weakly field dependent, and ${\mathit{R}}_{\mathrm{Ag}\mathrm{-}\mathrm{Co}}$(H) is strongly field dependent: ${\mathit{AR}}_{\mathrm{Ag}\mathrm{-}\mathrm{Co}}$(H), where A is the sample area, decreases from ≊0.6 fΩ ${\mathrm{m}}^2$ at the initial field ${\mathit{H}}_0$=0, to ≊0.2 fΩ ${\mathrm{m}}^2$ at the saturation field, ${\mathit{H}}_{\mathit{s}}$.