# Calculated Curie temperatures for rare-earth permanent magnets: ab initio inspection on localized magnetic moments in d-electron ferromagnetism

## TL;DR

This paper calculates Curie temperatures for rare-earth permanent magnets using ab initio methods and an effective spin model, providing insights into magnetic properties and their dependence on rare-earth elements.

## Contribution

It introduces a combined ab initio and spin model approach to predict Curie temperatures in rare-earth magnets, highlighting the trend consistency with experimental data.

## Key findings

- Calculated Curie temperatures align with experimental trends.
- The effective spin model's validity is limited by exchange coupling ranges.
- Quantitative comparisons reveal the model's accuracy and limitations.

## Abstract

We present a data set of calculated Curie temperatures for the main-phase compounds of rare-earth permanent magnets. We employ ab initio electronic structure calculations for the itinerant ferromagnetism and an effective spin model for the finite-temperature magnetism. Curie temperatures are derived on the basis of a classical Heisenberg model mapped via Liechtenstein's formula for atomic-pair-wise exchange couplings. Relative trends with respect to the species of rare-earth elements in calculated Curie temperatures for R2Fe14B are in agreement with experimental trends. Quantitative comparison between calculation and experimental data found in the literature point to an effective range of the exchange couplings imposing a limit on the validity range of the effective spin model.