Neutral vacancy-defect-induced magnetism in SiC monolayer

Abstract

We perform first-principles calculations to investigate the spin-polarization of vacancy defects in SiC monolayer. We show that Si and C vacancy defects play different roles in the magnetism of SiC monolayer. Local magnetic moments can be induced by the presence of Si vacancy (V Si) whereas no spin-polarization occurs in C vacancy (V C) defects. The induced states are due to the unpaired electrons on carbon atoms surrounding the silicon vacancy. Interestingly, starting from different initial spin distributions, two spin configurations with S=1 and 2 are obtained, and the energy difference between them is only 39 meV. The spatial distribution of spin density displays the features of ferrimagnetic alignments for the most stable configuration.