Defect-induced magnetism in χ3 borophene

Borophene is an emerging and promising twodimensional material for spintronics applications.Nevertheless,the origin and controllability of its magnetism remain poorly understood,thereby hindering the further development of borophene-based devices.In this study,it is demonstrated that χborophene with vacancy defects,which contains zigzag edges and dangling bonds,exhibits spin polarization.To understand the origin and characteristics of its magnetism,a magnetic study of vacancy defects in χborophene using first-principles calculations was performed.It is determined that the unpaired dangling bond electrons in the σ state contribute to its magnetism,and the zigzagged vacancy structure helps to maintain the localization and stability of unpaired electrons.Ferromagnetic coupling is completed by the s-p orbital interaction and mediated by p-orbital itinerant electrons.The magnetic coupling energy difference oscillates with the distance of magnetic atoms because of the indirect magnetic exchange by itinerant electrons and electronic shielding,in accordance with the Ruderman-Kittel-Kasuya-Yosida(RKKY)model.Furthermore,the causality between the dangling bonds and magnetism is identified by saturating magnetic B atoms using H,C and N atoms.This study provides a reference for the regulation of borophene in magnetic semiconductors.