Accession Number : ADA130900

Title :   Study of Materials Having Significance for High Energy Magnet Production and for Hydrogen Storage.

Descriptive Note : Final rept. 1 Jul 80-30 Jun 83,

Corporate Author : PITTSBURGH UNIV PA DEPT OF CHEMISTRY

Personal Author(s) : Wallace,W E

PDF Url : ADA130900

Report Date : 15 Jul 1983

Pagination or Media Count : 14

Abstract : The work carried out between July 1, 1980 and June 30, 1983 is described in detail in 6 review articles and 38 articles providing accounts of original work. The distribution of published papers is as follows: Journal of Magnetism and Magnetic Materials - 10, Solid State Communications - 6, Journal of the Less-Common Metals - 5, Journal of Applied Physics - 4, Journal of Solid State Chemistry - 4, Journal of Physical Chemistry -3, Journal of Physics and Chemistry of Solids -1, and chapters in various books - 11. A considerable part of the work has been concerned with the Zr Effect, the benefication of permanent magnet properties of rare earth-cobalt systems by doping with small amounts (1 wt%) of Zr (or Ti or Hf). It has been found that Zr replaces Co in R2Co17 systems, and this results in a sharp increase in magnetocrystalline anisotropy. This is responsible for part (but undoubtedly not all) of the Zr effect. Systems such as ErPrC017 are found to exhibit enhanced magnetocrystalline anisotropy, compared to Er2C017 or Pr2C017, since Er and Pr are observed to preferentially occupy the 2b and 2d sites, respectively. In these sites each has uniaxial anisotropy, as predicted from single ion anisotropy theory. Preferential site occupancy occurs because of the size difference between Er and Pr. Similar effects are observed in RPrC017 systems wit R = Tm or Yb.

Descriptors :   *Permanent magnets, Magnetic materials, *Rare earth elements, Anisotropy, Storage, Hydrogenation, Hydrides, Surface chemistry, Kinetics, Alloys, Literature surveys

Subject Categories : Physical Chemistry
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE