Research to Investigate Fundamental Magnetic Interactions in Selected Materials

摘要

Section I of this report describes the continuing investigation of intermetallic compounds or the type Co5R, where R is yttrium or a rare earth, as permanent magnet materials. The theoretical interpretation of the behavior of these materials based on domain boundary nucleation and motion has been refined, and further calculations are presented. Experimental results verifying this model have been obtained. A sensitivity of the coercive force to surface condition predicted by this model was confirmed experimentally. The investigation of the stability of Co5R materials in particle form has continued. Section II describes the investigation of several materials near the Curie point. Both CrO2 and nickel are found to obey the same special equation of state. When analyzed in this way, both ordered and disordered FePd3 are found to deviate from predictions based on the molecular field model. The results obtained from an analysis of x-ray and neutron diffraction work on Co17Y2 and Co17Ho2 are described in Section III. (Author)