Negative differential resistance in a family of Fe3X4 (X <b>=</b> S, Se, Te) antiferromagnetic semiconducting nanowires

Abstract

The experimentally observed 2D magnets have unlocked the possibility of realizing a stable long-range order in the low-dimensional limit, which also gives a boost to the family of 1D magnets. Recently, a family of Fe-based nanowires has been observed in high-throughput transition metal chalcogenides synthesized by chemical vapor deposition [Zhou et al., Nat. Mater. 22, 450–458 (2023)]. In this work, the atomic configuration, chemical composition, and magnetic properties of Fe3X4 (X = S, Se, Te) nanowires were confirmed by first-principles calculations and Monte Carlo simulations. Due to their intrinsic anisotropic character and strong d-p hybridization, Fe3X4 nanowires exhibit antiferromagnetic semiconducting behavior with good stability, a tunable bandgap of 0.277–0.771 eV, a large vertical magnetic anisotropy energy of 2.39 meV/Fe, and a high Néel temperature of 680–840 K. Moreover, the calculation of the spin transport properties has shown that these Fe3X4 nanowires possess the negative differential resistance behavior with the peak-to-valley current ratio from 1.84 to 6.85. Our results not only expand the database of magnetic nanowires but also provide a low-dimensional platform for multifunctional spin devices.