Studies of a High-Coercivity Electrodeposit Having a Lamellar Structure

Abstract

A cobalt-nickel-phosphorus electrodeposit having a 60-cycle coercive force of 1000 oe has been studied. Electron micrographs of the surface indicate that a lamellar structure is present. The lamellas occur in oriented clusters. Diffraction and magnetic studies show the material to be hexagonal with its uniaxial easy direction of magnetization (c axis) in the plane of the film. A Bitter pattern technique utilizing the high resolving power of the electron microscope shows that in a demagnetized sample, fields leave the plane of the film at lamellas cluster boundaries. In a magnetized sample, no fields leave the plane of the film. Studies of cross sections confirm the existence of the lamellar cluster structure. The results are explained on the basis of a model which considers each lamella to be a single-domain particle.