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. Our largest value with MR 80% is for a Co(10 angstrom)/Cu(10 angstrom) multilayer 340 angstrom 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 angstrom where values of MR are 11% and the magnetic hysteresis loops show structure. The MR is isotropic within +/- 1% except for demagnetization. We prefer a model where the interface disorder is responsible for the large change in resistivity by restricting the conduction electron mean free path.