Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1516705 | Journal of Physics and Chemistry of Solids | 2010 | 7 Pages |
First principles FLAPW-GGA calculations have been performed to understand the peculiarities of stability, elastic, electronic properties and chemical bonding for cubic carbides of four noble metals M=Rh, Pd, Ir and Pt depending on carbon stoichiometry: MC versus M4C. Our main findings are as follows: (i) in contrast to mono-carbides MC with positive formation energies Eform>0, carbon-deficient sub-carbides M4C are stable (Eform<0), thus carbon stoichiometry is one of the major factors determining successful synthesis of these materials, and (ii) as distinct from the majority of other 3d–5d metals (including Pd and Pt examined here), an unusual effect of Rh and Ir “metallization” and the increasing of ductility for these metals owing to the introduction of carbon has been established.