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Title: Low temperature route for the synthesis of rare earth transition metal borides and their hydrides

Synthesis of rare earth-based alloys by the ORD technique consists in the reduction of rare earth oxides in a melt of calcium under argon, and simultaneous diffusion-reaction of the just formed rare earth metal with the other elements. This method has been applied with success to numerous ternary borides containing transition metals such as the magnetic alloys Y{sub 2}Co{sub 14}B, LnCo{sub 4}B, and YCo{sub 3}B{sub 2}. By using a small excess of Ca, boride particles grow in a viscous slurry media containing unreacted (melted) Ca and nanosize CaO particles. Single phase boride alloys can be obtained at 1000{degrees}C as loose micrometer-size particles of very high crystal quality as confirmed by the sharp diffraction peaks on the corresponding X-ray diagrams. Particles can be easily recovered by gentle wishing in diluted weak acid solution, and dried under vacuum at room temperature. This rather low temperature technique is particularly adapted to the synthesis of incongruent melting phases, as well as for the alloys containing volatile rare earth elements (Sm, Yb, Tb,...).
Authors:
; ;  [1]
  1. CNRS UMR 5628, Saint Martin d`Heres (France)
Publication Date:
OSTI Identifier:
569537
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 133; Journal Issue: 1; Other Information: PBD: Oct 1997
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; YTTRIUM BORIDES; COBALT BORIDES; MAGNETIC PROPERTIES; SYNTHESIS; MICROSTRUCTURE; X-RAY DIFFRACTION