# Effect of hydrostatic pressure on ferromagnetism in two-dimensional CrI$_3$

## TL;DR

This study explores how hydrostatic pressure influences the magnetic properties of layered ferromagnetic semiconductor CrI$_3$, revealing increased Curie temperature and coupled spin-lattice effects.

## Contribution

It provides new insights into pressure-induced modifications of magnetic phase transitions and inter-layer interactions in CrI$_3$, a 2D ferromagnetic material.

## Key findings

- Curie temperature increases from 60.4 K to 64.9 K under pressure
- Pressure sharpens the magnetic transition and reduces hysteresis
- Inter-layer coupling and bond angles change with pressure

## Abstract

We have investigated the magnetic properties of highly anisotropic layered ferromagnetic semiconductor CrI$_3$ in presence of hydrostatic pressure ($P$). At ambient pressure, magnetization exhibits a clear anomaly below 212 K along with a thermal hysteresis over a wide temperature range (212-180 K), where a first-order structural transition is observed. CrI$_3$ undergoes a second-order ferromagnetic-paramagnetic phase transition with Curie temperature $T_C$=60.4 K. With application of pressure, the transition becomes sharper and $T_C$ is found to increase from 60.4 to 64.9 K as $P$ increases from 0 to 1.0 GPa. $T_C$ increases with $P$ in a sublinear fashion. The thermal hysteresis in magnetization and the increase of $T_C$ with pressure suggest that the spin and lattice degrees of freedom are coupled. The observed increase in $T_C$ has been explained on the basis of change in inter-layer coupling and Cr-I-Cr bond angle with pressure.