High magnetoresistance and low coercivity in electrodeposited Co∕Cu granular multilayers

Abstract

Co ∕ Cu multilayers were electrodeposited from a single solution electrolyte. By reducing the magnetic layer thickness from 1to0.2nm, samples with heterogeneous mixture of ferromagnetic and superparamagnetic clusters have been made. Magnetization and magnetotransport measurements revealed the structured evolution of the multilayer granular samples. With critical thickness of tCo∼0.5nm, room temperature magnetoresistance of 7% was obtained at 2kOe with hysteresis of 70Oe. The large magnetoresistance obtained in granular multilayers is attributed to the presence of a range of sizes for the Co particles.