Defects in CrSBr visualized by Scanning Tunneling Microscopy

Chromium sulfur bromide (CrSBr) is a 2D magnetic semiconducting material with a rectangular lattice that has attracted a lot of attention in recent years as it combines a rich magnetic phase diagram with axis-dependent electronic and optical properties. The presence of defects in CrSBr is believed to be connected to the details of the magnetic order and excitonic responses, yet their nature, structure and electronic properties are not fully understood. In this work, we use scanning tunneling microscopy/spectroscopy to study the defect density of CrSBr crystals. We observe two types of defects, whose electronic structure is most prominent near the edge of the CrSBr valence band, and have similar symmetries to the underlying lattice. Using density of states maps, we visualize the spatial extent of the defect-induced electronic states in CrSBr. In addition, by increasing the bias applied through STM, we observe structural changes in close proximity to defects, leading to a potential avenue for defect engineering in CrSBr.