Magnetization and magnetoresistance of Co/Cu layered films

Multilayer Co/Cu and sandwich layer Co/Cu/Co films made by magnetron sputtering using no special layering elements give the oscillatory magnetic coupling and magnetoresistance (MR) previously reported. The largest value with MR 80% is for a Co(10 Å)/Cu(10 Å) multilayer 340 Å thick. The increase of resistivity in small magnetic fields is the source of the MR. The MR is small in the sandwich layer films until Cu thicknesses above 23 Å where values of MR are 11% and the magnetic hysteresis loops show structure. The MR is isotropic within ±1% except for demagnetization. The authors prefer a model where the interface disorder is responsible for the large change in resistivity by restricting the conduction electron mean free path