Investigation on high magnetoresistance Ni0.81Fe0.19 films grown on (Ni0.81Fe0.19)1−xCrx underlayers

We have fabricated Ni0.81Fe0.19 films with (Ni0.81Fe0.19)1−xCrx films as underlayers by dc magnetron sputtering, the results show that larger anisotropic magnetoresistance (ΔR/R) values of Ni0.81Fe0.19 films are observed using the underlayers with Cr concentration of ∼36 at.% at an optimum underlayer thickness of ∼4.4 nm, the maximum AMR value is 3.35%. The results of atomic force microscope (AFM) and X-ray diffraction (XRD) show that the ΔR/R enhancement is attributed to the formation of large average grain size and the strong(111) texture in the Ni0.81Fe0.19 films.