Determination of Certain Properties and Characteristics of Rare Earth Metals, Laser Crystals, Semiconductors, and Dielectric Materials

摘要

Intermetallic phases of cobalt with several rare earth metals can be used to produce permanent magnets. Energy products up to 36 MGOe, more than three times the value for the best commercially available magnets, are theoretically possible. SmCo5 and PrCo5 magnets with more than 20 MGOe have been made, and a record value of 23 MGOe has been attained with a mixture of these in the laboratory by powder metallurgy processes. Alloying additions of copper and iron to some of the alloys has also made it possible to obtain good permanent magnetic properties in cast samples. The report discusses the following: The physical metallurgy of rare earth-cobalt alloy systems; The structure and properties of related rare earth iron intermetallic phases; A general review of the development of permanent magnets based on cobalt and the rare earths including the physical concepts, metallurgical problems, production methods, and economic factors associated with commercial applications. The influences of metallurgical processing varibles on the magnetic properties of copper and iron substituted rare earth-cobalt magnetic alloys are discussed. A summary of work performed with laser crystal materials and dielectric measurement techniques is also presented. (Author)