Cerium as a possible stabilizer of ThMn${}_{12}$-type iron-based compounds: A first-principles study

Abstract

The structural stability of CeFe${}_{12}$ is investigated by using first-principles calculation. The formation energies of CeFe${}_{12}$ relative to the Ce${}_2$Fe${}_{17}$ + bcc-Fe phase and to the CeFe${}_2$ + bcc-Fe phase are calculated with the assumptions of trivalency and tetravalency for Ce. Those values are compared with corresponding results in $R$Fe${}_{12}$ for $R=$ Nd, Sm, and Zr. Our results suggest that the tetravalent Ce is a promising stabilizer of the ThMn${}_{12}$ structure. We also show that the stabilizing effect of an element depends as much on the valency as on the size of the $R$ element by investigating $R$Fe${}_{12}$ where $R$ is assumed to have a hypothetical valency on the basis of first-principles calculation.

5pages, 4figures