Prediction of half-semiconductor antiferromagnets with vanishing net magnetization

Abstract

Half-metallic antiferromagnets have proven to be promising candidates for spintronic applications, since the zero net magnetization leads to low stray fields. Here, using a self-consistent DFT + U approach, we found that in a two-dimensional semiconductor codoped with different transition metal pairs, spin-polarized electrons and zero magnetization co-exist. We systematically investigated a Fe–Cr codoped monolayer boron nitride (BN) sheet. Interestingly, the Fe–Cr codoping in the BN sheet induces a half-semiconductor feature, with fully spin-polarized valence and conduction bands belonging to the same spin channel and completely compensated spontaneous magnetization. We propose that this type of materials are half-semiconductor antiferromagnets (HSCAF). Spin gapless semiconductor antiferromagnets (SGSAF) with zero net magnetism are also achieved in such codoped systems. Moreover, we find that HSCAF can be realized in other two-dimensional materials, such as monolayer AlN and GaN with Cr–Ni and Mn–Co codoping, respectively. The HSCAF and SGSAF not only represent promising candidates for spintronics, but also enrich the concept of magnetic materials.