ABSTRACT Two‐dimensional (2D) Fe‐based nanosheets have sparked wide attention owing to exotic magnetism, superconductivity and topological phases. However, the synthesis of 2D Fe m X n ( X = Te/Se/S, m , n : integer), typically in a non‐stoichiometric ratio, remains challenging because of narrow thermodynamic windows. Here, 2D Fe m X n nanosheets were successfully prepared by independent regulation of reaction kinetics under the magnet‐assisted chemical vapor deposition (CVD) strategies. Atomic‐resolution scanning transmission electron microscopy (STEM) analysis shows that the obtained nanosheets are highly crystalline with smooth surfaces. They are identified as orthorhombic FeTe 2 , vacant Fe 3 Se 4 , and Fe 7 S 8 . Furthermore, magneto‐transport measurements are conducted on these three kinds of 2D nanosheets by fabricating Hall bar devices. Orthorhombic FeTe 2 exhibits a semiconductor nature and apparent weak antilocalization (WAL), indicative of multiple conduction channels or competing scattering mechanisms. Vacant Fe 3 Se 4 with metallic behavior shows an apparent crossover of magnetoresistance (MR), which is positive and negative below and above 17 K. Importantly, 2D Fe 7 S 8 nanosheets feature a typical Besnus transition at about 32 K, below which a significantly huge coercive field (≤ 3 T) dramatically appears. This Besnus transition in 2D Fe 7 S 8 probably resulted from a structure transition from a high‐temperature monoclinic phase to a low‐temperature triclinic‐like state. Our work provides an effective strategy to synthesize Fe‐based nanosheets, paving the way to investigate intriguing properties.
Zhang et al. (Mon,) studied this question.