Giant Positive Magnetoresistance in Magnetic Multilayer Film Prepared by Ion-Beam Sputtering

The magnetic multilayers Ni₇₈Co₂₂//Cu//Ni₇₈Co₂₂/Ni₇₈Co₂₂O//Ta were fabricated by ion-beam sputtering through applied magnetic field and treatment under high vacuum. Resistance against applied magnetic field was measured by the standard four-point probe method at room temperature. The giant positive magnetoresistance has been observed. A maximum positive magnetoresistance at room temperature was obtained to be 280%.