The role of interfaces on the magnetic behavior of granular CuFeCo alloys

Abstract

PACS 75.47.De, 75.50.Tt, 75.70.Cn, 76.80.+y Granular thin films of face centered tetragonal (fct) FeCo-clusters in a γ-CuCo matrix show a giant magneto resistance effect. Cu 100-x (Fe 50 Co 50 ) x samples with 63 ≤ x ≤ 88 were examined using Mössbauer Spectroscopy, electron microscopy, Magnetoresistance, SQUID and Rutherford Backscattering Spectroscopy. In ultrafine particles with fct-FeCo imbedded in a CuCo matrix the giant magneto resistance effect is strongly correlated to the ratio of interface/bulk. The magnetic interfaces form an additional scattering centere for the electrons which causes an increase of the GMR effect.