Surface Passivation and Tunable Magnetic Properties of Cr-Based MXenes

Abstract

MXene, a two-dimensional (2D) derivative of MAX compounds, due to their structural and compositional flexibility, is an ideal family of compounds to study a number of structure–property relations. In this work, we have investigated the tunability of magnetic properties in Cr-based MXenes, both pristine and surface passivated, that have an in-plane ordering arising out of alloying Cr with another nonmagnetic transition metal atom. Using density functional theory calculations, we have explored the effects of composition and surface functionalizations on the electronic and magnetic properties of these in-plane ordered MXenes known as i-MXenes. We found that the electronic and magnetic ground states are quite sensitive to their structure and composition. This provides enough tunability in these compounds that they can be used for practical applications. Our calculated results of magnetic transition temperatures and magnetic anisotropy energies are comparable to those of many established two-dimensional magnets. These combined results widen the prospect of these i-MXenes for multiple usages as magnetic devices, making them attractive for further investigation.