Return
Kinetic-Controlled Growth of Iron Chalcogenide Nanosheets Featuring Besnus Transition
H
J
Y
Y
L
Z
W
P
W
C
G
G
DOI:10.1002/rar2.70317.png)
Abstract
En 中文
Two-dimensional (2D) Fe-based nanosheets have sparked wide attention owing to exotic magnetism, superconductivity and topological phases. However, the synthesis of 2D FemXn (X = Te/Se/S, m, n: integer), typically in a non-stoichiometric ratio, remains challenging because of narrow thermodynamic windows. Here, 2D FemXn 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 FeTe2, vacant Fe3Se4, and Fe7S8. Furthermore, magneto-transport measurements are conducted on these three kinds of 2D nanosheets by fabricating Hall bar devices. Orthorhombic FeTe2 exhibits a semiconductor nature and apparent weak antilocalization (WAL), indicative of multiple conduction channels or competing scattering mechanisms. Vacant Fe3Se4 with metallic behavior shows an apparent crossover of magnetoresistance (MR), which is positive and negative below and above 17 K. Importantly, 2D Fe7S8 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 Fe7S8 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.
Keywords:
Besnus transition
chemical vapor deposition
FemXn
two-dimensional materials
Journal
IF:
11
Papers:
4.9K
Citations:
1.7W
