# Anisotropic ferromagnetism and structure stability in $4f$-$3d$ intermetallics: ab initio structure optimization and magnetic anisotropy for RCo$_5$ (R=Ce, La, and Y)

## TL;DR

This study uses first-principles calculations to explore the electronic mechanisms behind ferromagnetism and structural stability in $4f$-$3d$ intermetallics, focusing on RCo$_5$ compounds with potential for next-generation permanent magnets.

## Contribution

It provides a detailed ab initio analysis of the magnetic anisotropy and structural stability in RCo$_5$ compounds, highlighting their relevance for developing new permanent magnet materials.

## Key findings

- Electronic mechanisms influence ferromagnetism and stability in RCo$_5$.
- Comparison suggests RCo$_5$ as a candidate for mid-class magnets.
- Insights guide future material design for permanent magnets.

## Abstract

Electronic mechanism in the interplay between ferromagnetism and structure stability of $4f$-$3d$ intermetallics in the main phase of rare-earth permanent magnets is investigated from first principles. We present a case study with an archetypical materials family RCo$_5$ (R=Ce, La, Y), which was a part of the earliest rare-earth permanent magnets and from which other representative main-phase compounds can be regarded as a derived type. Comparison with the champion magnet materials family R$_2$T$_{14}$B and recently revisited materials family RT$_{12}$ (T=Co and Fe) points to a direction leading to a mid-class magnet for the possible next generation materials.