A three-stage magnetic phase transition revealed in ultrahigh-quality van der Waals magnet CrSBr

TL;DR

This study reports the synthesis of ultrahigh-quality CrSBr van der Waals magnets, revealing a three-stage magnetic phase transition through thermodynamic anomalies, with implications for spintronic applications.

Contribution

The paper introduces a method to synthesize ultrahigh-quality CrSBr crystals and uncovers a three-stage magnetic transition not previously observed in this material.

Findings

Identification of three thermodynamic anomalies at 185K, 156K, and 132K.

High crystallinity confirmed by multiple advanced characterization techniques.

Potential for integration into 2D heterostructures for spintronics.

Abstract

van der Waals (vdW) magnets are receiving ever-growing attention nowadays due to their significance in both fundamental research on low-dimensional magnetism and potential applications in spintronic devices. High crystalline quality of vdW magnets is key for maintaining intrinsic magnetic and electronic properties, especially when exfoliated down to the 2D limit. Here, ultrahigh-quality air-stable vdW CrSBr crystals are synthesized using the direct vapor-solid synthesis method. The high single crystallinity and spatial homogeneity have been thoroughly evidenced at length scales from sub-mm to atomic resolution by X-ray diffraction, second harmonic generation, and scanning transmission electron microscopy. More importantly, specific heat measurements of these ultrahigh quality CrSBr crystals show three thermodynamic anomalies at 185K, 156K, and 132K, revealing a stage-by-stage development of the magnetic order upon cooling, which is also corroborated with the magnetization and transport results. Our ultrahigh-quality CrSBr can further be exfoliated down to monolayers and bilayers easily, paving the way to integrate them into heterostructures for spintronic and magneto-optoelectronic applications.