Magnetoresistance in FeSi/Cu Compositionally Modulated Films

FeSi/Cu compositionally modulated amorphous films with different thicknesses of Cu layers have been obtained by radio-frequency sputtering. We studied the resistivity and magnetoresistance of these samples at room temperature. The resistivity of FeSi/Cu compositionally modulated films (CMFs) increases with decreasing the thickness of Cu layers. The FeSi/Cu CMFs show a negative magnetoresistance effect. The magnetoresistance decreases with decreasing the Cu layer thickness d, when d_c, is over 20Å, but it turns to increase with decreasing d_c, when d_c, is below 20Å. This is probably caused by the polarization of conductive electrons of Cu.