Influence of intermediate layers on coercive force of laminated Co-P films

Abstract

This paper investigated the coercive force (H c ) of laminated Co-P films. The films were laminated by introducing intermediate layers of Pd ( T \sim 25 A) or nonmagnetic Ni-P (T = 250 A) between the Co-P films. The thickness of the Co-P films was varied from 650 A to 2600 A but was maintained constant within any series of laminations. The H c was evaluated as a function of total thickness for multiple Co-P laminate thicknesses up to 10,000 A. The H c of laminated Co-P films with intermediate Pd layers increased with total lamination thickness regardless of the thickness of the individual Co-P film. However, Co-P laminates deposited from a dilute solution with intermediate layers of Ni-P exhibited H c values independent of the total lamination thickness. The H c was independent of the total lamination thickness regardless of the base material provided Ni-P was deposited as the substrate. The magnitude of the H c was dependent on the Co-P film thickness. The H c of such Co-P laminates can be adjusted from 340 Oe to 700 Oe by selection of the appropriate thickness of the Co-P film. Co-P laminates deposited from a concentrated solution with intermediate layers of Ni-P exhibit H c values which decrease with total lamination thickness. These films exhibited lower H c values than nonlaminated Co-P films.