Orbital Analysis of Electronic States for vdW Material CoPS₃ by Scanning Probe Microscopy

Abstract

Two-dimensional planar antiferromagnets on the basis of transition metal phosphorus trichalcogenides (MPX3) have recently attracted much attention owing to the possibility of exfoliating these materials and potentially implementing them in spintronic heterostructures. For the purpose of designing particular interfaces with graphene or other two-dimensional materials, knowledge of the real-space atomic distributions in the MPX3 layers is essential. Here, by using scanning probe microscopy in combination with ab initio calculations, we investigate the real-space structure of van der Waals material CoPS3 down to the atomic level. We observe that the voltage dependence of scanning tunneling microscopy imaging shows distinct atomic signatures, which, upon comparison to the density functional theory results, can be directly attributed to different orbital contributions. The observed orbital fingerprints suggest the high spin ground state for Co2+ ions (S = 3/2) and energy-dependent hybridization effects between atomic orbitals of Co, P, and S, thus providing valuable insight into the magnetic and electronic states of this van der Waals material.