Defect induces room temperature ferromagnetism and half-metallicity in Zr2CO2 MXene: Ab-initio calculations

Recently, substitutional doping in two-dimensional (2D) materials is demonstrated via chemical vapor deposition (CVD), opening a new strategy for designing and constructing novel ferromagnetic materials. Substitutional doping of Cr doping at possible dopant sites in Zr2CO2 monolayer is systematically studied using ab-initio calculations. It is found that Cr prefers Zr-site with suitable bond length and apparent charge transfer to host material, which is also supported by the lowest negative formation energy. In all studied cases, Cr atoms form strong bond to the Zr2CO2 crystal, a possible signature magnetization in non-magnetic Zr2CO2 monolayer. Ferromagnetic (FM) and anti-ferromagnetic (AFM) coupling calculations disclose that Cr doped at the Zr-site has a FM ground state. Moreover, using the mean-field theory (MFT) and Quantum Monte-Carlo (QMC) simulations, the transition temperature is calculated to be 184.76 K and 411 K, respectively. Our findings predict possible room temperature ferromagnetism in Cr-doped 2D MXene materials for possible spintronics device applications.