Harold J. Garrett

Magnetization reversal process in RCo5 particles and sintered permanent magnets

A model relating the nucleation field for particles of R Co5‐type permanent‐magnet materials (R represents the rare‐earth element) to domain wall energy is shown to describe all our experiments, and that it is also consistent with previously reported data for single‐crystal particles and powders of SmCo5. The model is also consistent with sintered permanent‐magnet data and suggest that a drastic reduction of oxygen pick up in the manufacturing process would greatly improve SmCo5 permanent magnets.

A Sm2 (Co,Fe)17 magnet with (BH)max = 12 MG Oe

A sample of sputtered Sm2(Co0.7Fe0.3)17 was found to have mHc=5600 Oe and (B H)max=12 MG Oe after heat treatment. These are both record values for 2:17 alloys, and the energy product is a record value for an isotropic magnet. This material is the first 2:17 alloy to exhibit useful permanent‐magnet properties.

Die Forming Doubly Focusing X‐Ray Monochromators

Reliable forming techniques for the preparation of doubly curved LiF x‐ray monochromators are described. These techniques are applicable to the formation of doubly focusing one piece monochromating crystals with geometries suited to a wide range of experimental requirements. The resulting dislocation structures were analyzed and utilized in the development of the techniques and are presented as a guide for the preparation of similar focusing crystals.