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

## TL;DR

This study uses first-principles calculations to explore cerium's potential as a stabilizer for ThMn$_{12}$-type iron compounds, highlighting the importance of valency and size in stabilization.

## Contribution

It demonstrates that tetravalent cerium can effectively stabilize ThMn$_{12}$-type structures, providing insights into element valency and size effects on stability.

## Key findings

- Tetravalent Ce is a promising stabilizer for ThMn$_{12}$ structure.
- Stabilizing effects depend on both valency and atomic size.
- Ce's valency influences its stabilizing ability in Fe-based compounds.

## 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.