# Anisotropic magnetic entropy change in Cr$_2$X$_2$Te$_6$ (X = Si and Ge)

## TL;DR

This study investigates the anisotropic magnetic entropy change in 2D ferromagnetic semiconductors Cr$_2$X$_2$Te$_6$ (X=Si, Ge), revealing significant entropy changes and universal critical behavior indicative of 2D Ising magnetism, relevant for spintronics.

## Contribution

It provides the first detailed analysis of magnetic entropy change and critical behavior in Cr$_2$X$_2$Te$_6$ monolayers, confirming 2D Ising-like ferromagnetism and magnetocrystalline anisotropy effects.

## Key findings

- Cr$_2$Si$_2$Te$_6$ exhibits a maximum magnetic entropy change of ~5.05 J kg$^{-1}$ K$^{-1}$.
- Cr$_2$Ge$_2$Te$_6$ shows a maximum entropy change of ~2.64 J kg$^{-1}$ K$^{-1}$.
- Rescaled entropy change curves collapse onto a universal curve, indicating similar critical behavior.

## Abstract

Intrinsic, two-dimensional (2D) ferromagnetic semiconductors are an important class of materials for spintronics applications. Cr$_2$X$_2$Te$_6$ (X = Si and Ge) semiconductors show 2D Ising-like ferromagnetism, which is preserved in few-layer devices. The maximum magnetic entropy change associated with the critical properties around the ferromagnetic transition for Cr$_2$Si$_2$Te$_6$ $-\Delta S_M^{max} \sim$ 5.05 J kg$^{-1}$ K$^{-1}$ is much larger than $-\Delta S_M^{max} \sim$ 2.64 J kg$^{-1}$ K$^{-1}$ for Cr$_2$Ge$_2$Te$_6$ with an out-of-plane field change of 5 T. The rescaled $-\Delta S_M(T,H)$ curves collapse onto a universal curve independent of temperature and field for both materials. This indicates similar critical behavior and 2D Ising magnetism, confirming the magnetocrystalline anisotropy that could preserve the long-range ferromagnetism in few-layers of Cr$_2$X$_2$Te$_6$.