Pressure dependence of magnetoresistance for Fe/Cr multilayers

Abstract

The magnetoresistance (MR) in Fe/Cr magnetic multilayers (MML) has been measured under high pressure up to 2.5 GPa. It is found that the spin-dependent scattering plays an important role in the pressure dependence of MR ratio. In the present work, for [Fe(20/spl Aring/)/Cr(10 /spl Aring/)]/sub 20/ MML with antiferromagnetic (AF) state, the pressure coefficient of saturation field H/sub s/ is (1/H/sub s/)(/spl part/H/sub s///spl part/P)=3.3/spl times/10/sup -2/ GPa/sup -1/ between 0.1 and 2.5 GPa. We found that the (1/|J|)(/spl part/|J|//spl part/P) for AF-Fe/Cr MML with polycrystalline structure is opposite in sign to that with epitaxial one. For [Fe(20 /spl Aring/)/Cr(22/spl Aring/)]/sub 20/ MML with ferromagnetic (F) state, anisotropic magnetoresistance (AMR) decreases with increasing pressure. It is suggested that the anisotropy constant decreases with weakening spin-orbit interaction at high pressure. At high field, the AMR is easily suppressed by applying pressure while the giant magnetoresistance around H/sub s/ increases slightly with increasing pressure for polycrystalline Fe/Cr MML.