Tailoring Magnetism in Self-intercalated Cr1+{\delta}Te2 Epitaxial Films

TL;DR

This study demonstrates the ability to systematically tune magnetic properties such as Curie temperature and anisotropy in self-intercalated Cr1+{ extdelta}Te2 epitaxial films, advancing their potential for spintronic devices.

Contribution

We present a method to control magnetism in TMD films via self-intercalation, achieving tunable Tc and magnetic anisotropy in epitaxial Cr1+{ extdelta}Te2 films.

Findings

Tc increased from 160K to 350K with increasing { extdelta}

Magnetic anisotropy rotated from out-of-plane to in-plane

Ab initio calculations suggest antiferromagnetic interactions influence magnetic behavior

Abstract

Magnetic transition metal dichalcogenide (TMD) films have recently emerged as promising candidates to host novel magnetic phases relevant to next-generation spintronic devices. However, systematic control of the magnetization orientation, or anisotropy, and its thermal stability, characterized by Curie temperature (Tc) remains to be achieved in such films. Here we present self-intercalated epitaxial Cr1+{\delta}Te2 films as a platform for achieving systematic/smooth magnetic tailoring in TMD films. Using a molecular beam epitaxy (MBE) based technique, we have realized epitaxial Cr1+{\delta}Te2 films with smoothly tunable over a wide range (0.33-0.82), while maintaining NiAs-type crystal structure. With increasing {\delta}, we found monotonic enhancement of Tc from 160 to 350 K, and the rotation of magnetic anisotropy from out-of-plane to in-plane easy axis configuration for fixed film thickness. Contributions from conventional dipolar and orbital moment terms are insufficient to explain the observed evolution of magnetic behavior with {\delta}. Instead, ab initio calculations suggest that the emergence of antiferromagnetic interactions with {\delta}, and its interplay with conventional ferromagnetism, may play a key role in the observed trends. To our knowledge, this constitutes the first demonstration of tunable Tc and magnetic anisotropy across room temperature in TMD films, and paves the way for engineering novel magnetic phases for spintronic applications.