Spin gapless semiconductors in antiferromagnetic monolayer HC[formula omitted]N[formula omitted]BN under strain

Abstract

A density functional study is presented for HC4N3BN monolayer, which is triazine g-C4N3 tailored with H at its graphitic sites and B plus N at vacant sites, under uniaxial or biaxial in-plane strain. For moderate strains up to about ±8 percent, first-principles molecular dynamics simulations prove its thermal stability at room temperature and electronic structure calculations show the persistence of antiferromagnetic ground state of the system. The material undergoes magnetic transitions to ferro- and ferrimagnetic orders respectively at the critical biaxial strain of −8.3% and uniaxial strain of 7.8%. Interestingly, both transitions occur when the electronic structures of strained systems show the character of a spin gapless semiconductor. The combined effect of spin charge transfer and band shifting is proposed as a possible explanation for these transitions. Our finding on this monolayer signifies the importance of strain engineering in designing novel materials for antiferromagnetic spintronics.