Two-dimensional magnets could potentially revolutionize information technology, but their potential application to cooling technology and magnetocaloric effect (MCE) in a material down to the monolayer limit remain unexplored. Herein, we reveal through multiscale calculations the existence of giant MCE and its strain tunability in monolayer magnets such as CrX3 (X=F, Cl, Br, I), CrAX (A=O, S, Se; X=F, Cl, Br, I), and Fe3GeTe2. The maximum adiabatic temperature change (ΔTadmax), maximum isothermal magnetic entropy change, and specific cooling power in monolayer CrF3 are found as high as 11 K, 35 μJm−2K−1, and 3.5 nWcm−2 under a magnetic field of 5 T, respectively. A 2% biaxial and 5% a-axis uniaxial compressive strain can remarkably increase ΔTadmax of CrCl3 and CrOF by 230% and 37% (up to 15.3 and 6.0 K), respectively. It is found that large net magnetic moment per unit area favors improved MCE. These findings advocate the giant-MCE monolayer magnets, opening new opportunities for magnetic cooling at nanoscale.
@article{arxiv.2303.15722,
title = {Giant magnetocaloric effect in magnets down to the monolayer limit},
author = {Weiwei He and Yan Yin and Qihua Gong and Richard F. L. Evans and Oliver Gutfleisch and Baixiang Xu and Min Yi and Wanlin Guo},
journal= {arXiv preprint arXiv:2303.15722},
year = {2023}
}