# Converting Faraday rotation into magnetization in europium chalcogenides

## TL;DR

This paper introduces a simple semiclassical model that relates Faraday rotation to magnetization in europium chalcogenides, validated by experiments across various magnetic phases and temperatures, and discusses its broader applicability.

## Contribution

The paper presents a new, simple model linking Faraday rotation to magnetization in EuX compounds, validated experimentally and applicable across different magnetic states.

## Key findings

- Faraday rotation is proportional to magnetization in EuX.
- The proportionality depends only on wavelength and band gap.
- The model is validated across all EuSe magnetic phases.

## Abstract

We present a simple semiclassical model to sustain that in europium chalcogenides (EuX), Faraday rotation (FR) in the transparency gap is proportional to the magnetization of the sample, irrespective of the material's magnetic phase, temperature, or applied magnetic field. The model is validated by FR and magnetization measurements in EuSe in the temperature interval 1.7-300K, covering all EuSe magnetic phases (paramagnetic, antiferromagnetic type I or type II, ferrimagnetic and ferromagnetic). Furthermore, by combining the semiclassical model with the explicit electronic energy structure of EuX, the proportionality coefficient between magnetization and FR is shown to be dependent only on the wavelength and the band gap. Due to its simplicity, the model has didactic value, moreover, it provides a working tool for converting FR into magnetization in EuX. Possible extension of the model to other intrinsic magnetic semiconductors is discussed.