2019/02/28 by Dahlia R. Klein, David MacNeill, Qian Song +9 · 2 citations
Materials Science · Physics and Astronomy · #2D Materials and Applications #Antiferromagnetism #Chemical and Physical Properties of Materials #Ground state #Heusler alloys: electronic and magnetic properties #Magnetism #Monolayer #Quantum tunnelling #Raman spectroscopy #Stacking #cond-mat.mes-hall #cond-mat.mtrl-sci #van der Waals force
paper · pdf · doi:10.1038/s41567-019-0651-0
published as Nature Physics (2019)
arxiv created 2019/02/28 · openalex created_date 2019/03/11 · openalex publication_date 2019/09/16 · arxiv updated 2019/10/10 · openalex updated_date 2026/08/06
Following the recent isolation of monolayer CrI3, there has been a surge of new two-dimensional van der Waals magnetic materials, whose incorporation in van der Waals heterostructures offers a new platform for spintronics, proximity magnetism, and quantum spin liquids. A primary question in this burgeoning field is how exfoliating crystals to the few-layer limit influences their magnetism. Studies on CrI3 have shown a different magnetic ground state for ultrathin exfoliated films but the origin is not yet understood. Here, we use electron tunneling through few-layer crystals of the layered antiferromagnetic insulator CrCl3 to probe its magnetic order, finding a ten-fold enhancement in the interlayer exchange compared to bulk crystals. Moreover, temperature- and polarization-dependent Raman spectroscopy reveal that the crystallographic phase transition of bulk crystals does not occur in exfoliated films. This results in a different low temperature stacking order and, we hypothesize, increased interlayer exchange. Our study provides new insight into the connection between stacking order and interlayer interactions in novel two-dimensional magnets, which may be relevant for correlating stacking faults and mechanical deformations with the magnetic ground states of other more exotic layered magnets, such as RuCl3.