Low field giant magnetoresistance in sputtered permalloy/Au multilayers

Polycrystalline permalloy/Au multilayers exhibit oscillatory variations in saturation magnetoresistance as a function of increasing Au layer thickness. The change in resistance is saturated in fields as low as a few Oe at room temperature leading to changes in resistance per unit field of more than 1%/Oe. These are the largest room temperature magnetic field sensitivities yet reported in simple magnetic multilayers.