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Veith, G. M.

Publications and source records attributed to Veith, G. M..

12 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

Growth and Characterization of Ce- Substituted Nd 2 Fe 14 11 B Single Crystals

Single crystals of (Nd 1-x Ce x ) 2 Fe 14 B are grown out of Fe-(Nd,Ce) flux. Chemical and structural analysis of the crystals indicates that (Nd 1-x Ce x ) 2 Fe 14 B forms a solid solution until at least x = 0.38 with a Vegard-like variation of the lattice constants with x. Refinements of single crystal neutron diffraction data indicate that Ce has a slight site preference (7:3) for the 4g rare earth site over the 4f site. Furthermore, magnetization measurements show that for x = 0.38 the saturation magnetization at 400 K, a temperature important to applications, falls from 29.8 for the parent Nd 2 Fe 14 B to 27.6 μ B /f.u., the anisotropy field decreases from 5.5 T to 4.7 T, and the Curie temperature decreases from 586 to 543 K. First principles calculations carried out within density functional theory are used to explain the decrease in magnetic properties due to Ce substitution. Although the presence of the lower-cost and more abundant Ce slightly affects these important magnetic characteristics, this decrease is not large enough to affect a multitude of applications. Ce-substituted Nd 2 Fe 14 B is therefore a potential high-performance permanent magnet material with substantially reduced Nd content.

36 MATERIALS SCIENCE↗