Technology Development for Transition Metal-Rare Earth High-Performance Magnetic Materials
Semi-Annual interim technical rept. no. 1, 30 Jun-31 Dec 1970
GENERAL ELECTRIC CO SCHENECTADY NY RESEARCH AND DEVELOPMENT CENTER
Pagination or Media Count:
Magnetization reversal discontinuities were studied in samples consisting of a few particles or a single particle. Experiments with successive polishing treatments indicate that individual defects are responsible for the observed magnetization behavior. A particle of Co5Y showed a perfectly rectangular hysteresis loop and a maximum energy product of 27.6mGO3. It has been found possible to analyze complex single-particle loops into linear combinations of elementary loops, as though the particles consisted of independent sub-particles. Metallographic studies of as-cast and annealed alloys of various compositions indicated that annealing has little effect on the observed phase distribution. Polarized light studies of finished magnets showed a greater tendency toward multidomain structures in magnets with lesser properties. A technique for analyzing the rare earth present in a compound in the reduced state indicated that this may be substantially less than the total rare earth present. Studies of Co-Nd-Sm and Co-Pr-Nd-Sm, aimed toward energy products of 25 mGOe or more, indicate that Nd and Pr combined are more effective than Nd alone in increasing the saturation, and that the variation of properties in these alloys is quite different from what it is in the Co-Pr-Sm alloys. An energy product of 20 mGOe has been attained in a Co-Pr-Nd-Sm alloy, although the optimum composition has not yet been reached.
- Electrical and Electronic Equipment
- Properties of Metals and Alloys
- Electricity and Magnetism