No abstract

Means of preparing Co-P electrodeposits having a wide range of magnetic properties are discussed. X-ray diffraction data, electron micrographs, and Bitter patterns are presented. An explanation of the origin of the high coercivity is presented. Low flux density of the material is described, and a possible explanation is presented.

The effect of cold-working and annealing on fine particle Co–P and Co–N–P electrodeposits is described. It is shown that the rod-type structure is sensitive to both cold-working and annealing while the platelet structure is sensitive only to annealing. Quantitative differences in response to annealing are discussed. It is suggested that both rod and platelet particles are coated with a thin layer of nonmagnetic cobalt-cobalt phosphide or nickel-nickel phosphide. This nonmagnetic coating explains both the high coercivity of the samples and the effect of annealing.

Electrodeposited Co–P films have been prepared having coercivities of 1000 to 1300 oe in the plane of the film. The material has been studied by means of x-ray diffraction, electron microscopy, and the Craik technique. It is concluded that the material has a rod-like structure and that shape anisotropy is at least partially responsible for the observed coercivity. The magnetic properties of this material are compared with those of previously reported platelet materials. An attempt is made to explain the properties of both rod and platelet materials on the basis of single domain particle theory.

EFFECT OF ROUGHNESS ON OXIDATION OF Fe 5. The relative thickness of the wiistite layer in the oxide scale decreased as the roughness of the iron surface increased. This behavior showed that there was a lowered diffusion rate of iron ions through the wiistite layer that formed on a rough surface.6. The most likely reason for the lowered iron ion diffusion rate is the blocking of the diffusion path by small voids in the oxide scale that forms over rough surfaces. These voids, which were detected in the oxide layers on all roughened Specimens, but not on smooth ones, act as barriers to ion diffusion and thereby lower the rate at which a roughened specimen oxidizes.