Controlling Magnetism in the 2D van der Waals Antiferromagnet CrPS4 via Ion Intercalation

TL;DR

This paper shows how inserting ions into a 2D magnetic material can change its magnetic properties and improve its performance for electronic applications.

Contribution

The study demonstrates that ion intercalation can switch magnetic states and significantly enhance ordering temperatures in CrPS4.

Findings

Li+ intercalation turns CrPS4 from a semiconductor to a metal and changes its magnetic state from antiferromagnetic to ferromagnetic.

TBA+ intercalation increases the van der Waals gap and stabilizes in-plane ferromagnetism with a Curie temperature above 100 K.

Intercalation enhances magnon transport properties and makes them more isotropic.

Abstract

Two-dimensional (2D) van der Waals (vdW) magnetic materials
are
platforms in which inserting chemical species into their interlayer
gaps offers a powerful route to engineer magnetism. Here, we focus
on the A-type antiferromagnetic semiconductor CrPS4 (T
N = 38 K) and investigate its electronic and
magnetic properties upon intercalation of lithium (Li+)
and organic tetrabutylammonium (TBA+) ions using first-principles
calculations. Li+ incorporation induces a semiconductor-to-metal
transition in CrPS4 and triggers a switching from an out-of-plane
antiferromagnetism state to an in-plane ferromagnetic state. This
is accompanied by an increase of the ordering temperature, reaching
a 5-fold enhancement for Li0.5CrPS4. TBA+ intercalation expands the vdW gap, decoupling CrPS4 layers and stabilizing in-plane ferromagnetism with T
C > 100 K. Furthermore, it enhances magnon group velocities
and yields more isotropic magnon transport. This work highlights intercalation
as a powerful approach for tailoring magnetism, paving the way for
tunable 2D-layered magnetic materials for spintronic and magnonic
applications.

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