Peierls transition driven ferroelasticity in two-dimensional $d$-$f$ hybrid magnet

TL;DR

This paper predicts that doping-induced Peierls transition in GdI3 leads to ferroelasticity and multiferroic behavior, offering potential for flexible nanoscale applications.

Contribution

It introduces a theoretical identification of GdI3 as a multiferroic 2D material with strain-resilient ferroelastic domains driven by Peierls transition.

Findings

Peierls transition induces ferroelasticity in GdI3.

Doping alters magnetic states via electron-phonon coupling.

Triple ferroelastic domains enable strain self-relaxation.

Abstract

For broad nanoscale applications, it is crucial to implement more functional properties, especially those ferroic orders, into two-dimensional materials. Here GdI$_3$ is theoretically identified as a honeycomb antiferromagnet with large $4f$ magnetic moment. The intercalation of metal atoms can dope electrons into Gd's $5d$-orbitals, which alters its magnetic state and lead to Peierls transition. Due to the strong electron-phonon coupling, the Peierls transition induces prominent ferroelasticity, making it a multiferroic system. The strain from undirectional stretching can be self-relaxed via resizing of triple ferroelastic domains, which can protect the magnet aganist mechnical breaking in flexible applications.