scholarly journals Probing magnetism in atomically thin semiconducting PtSe2

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Ahmet Avsar ◽  
Cheol-Yeon Cheon ◽  
Michele Pizzochero ◽  
Mukesh Tripathi ◽  
Alberto Ciarrocchi ◽  
...  
Keyword(s):  
Long Range ◽  
Magnetic Moments ◽  
Transition Metal Dichalcogenides ◽  
Magnetic Ordering ◽  
Atomic Scale ◽  
First Principles Calculations ◽  
Microscopy Imaging ◽  
Transmission Electron ◽  
Metal Dichalcogenides ◽  
The One

Abstract Atomic-scale disorder in two-dimensional transition metal dichalcogenides is often accompanied by local magnetic moments, which can conceivably induce long-range magnetic ordering into intrinsically non-magnetic materials. Here, we demonstrate the signature of long-range magnetic orderings in defective mono- and bi-layer semiconducting PtSe2 by performing magnetoresistance measurements under both lateral and vertical measurement configurations. As the material is thinned down from bi- to mono-layer thickness, we observe a ferromagnetic-to-antiferromagnetic crossover, a behavior which is opposite to the one observed in the prototypical 2D magnet CrI3. Our first-principles calculations, supported by aberration-corrected transmission electron microscopy imaging of point defects, associate this transition to the interplay between the defect-induced magnetism and the interlayer interactions in PtSe2. Furthermore, we show that graphene can be effectively used to probe the magnetization of adjacent semiconducting PtSe2. Our findings in an ultimately scaled monolayer system lay the foundation for atom-by-atom engineering of magnetism in otherwise non-magnetic 2D materials.

Pristine edge structures of T′′-phase transition metal dichalcogenides (ReSe2, ReS2) atomic layers

Nanoscale ◽  
2020 ◽  
Vol 12 (32) ◽  
pp. 17005-17012
Author(s):  
Xiya Chen ◽  
Bao Lei ◽  
Yong Zhu ◽  
Jiadong Zhou ◽  
Zheng Liu ◽  
...  
Keyword(s):  
Scanning Transmission Electron Microscopy ◽  
Density Functional ◽  
Transition Metal Dichalcogenides ◽  
Density Functional Theory Calculations ◽  
Microscopy Imaging ◽  
Functional Theory ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Metal Dichalcogenides ◽  
T Phase

Atomically sharp pristine edges of ReSe2 atomic layers were identified with scanning transmission electron microscopy imaging and density functional theory calculations.

scholarly journals Revealing noncollinear magnetic ordering at the atomic scale via XMCD

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fridtjof Kielgast ◽  
Ivan Baev ◽  
Torben Beeck ◽  
Federico Pressacco ◽  
Michael Martins
Keyword(s):  
Ground State ◽  
Magnetic Circular Dichroism ◽  
Magnetic Moments ◽  
Magnetic Ordering ◽  
Atomic Scale ◽  
Angle Of Incidence ◽  
X Ray ◽  
First Time ◽  
X Ray Absorption ◽  
Magnetic Sublattices

AbstractMass-selected V and Fe monomers, as well as the heterodimer $${\text{Fe}}_1{\text{V}}_1$$ Fe 1 V 1 , were deposited on a Cu(001) surface. Their electronic and magnetic properties were investigated via X-ray absorption (XAS) and X-ray magnetic circular dichroism (XMCD) spectroscopy. Anisotropies in the magnetic moments of the deposited species could be examined by means of angle resolving XMCD, i.e. changing the X-ray angle of incidence. A weak adatom-substrate-coupling was found for both elements and, using group theoretical arguments, the ground state symmetries of the adatoms were determined. For the dimer, a switching from antiparallel to parallel orientation of the respective magnetic moments was observed. We show that this is due to the existence of a noncollinear spin-flop phase in the deposited dimers, which could be observed for the first time in such a small system. Making use of the two magnetic sublattices model, we were able to find the relative orientations for the dimer magnetic moments for different incidence angles.

scholarly journals The Photodetectors Based on Lateral Monolayer MoS2/WS2 Heterojunctions

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Caihong Li ◽  
Juntong Zhu ◽  
Wen Du ◽  
Yixuan Huang ◽  
Hao Xu ◽  
...  
Keyword(s):  
Communication Systems ◽  
Transition Metal Dichalcogenides ◽  
Chemical Vapor ◽  
Large Area ◽  
Optical Signals ◽  
Metal Dichalcogenides ◽  
One Step ◽  
The One ◽  
Charge Carrier Trapping ◽  
Sharp Interfaces

AbstractMonolayer transition metal dichalcogenides (TMDs) show promising potential for next-generation optoelectronics due to excellent light capturing and photodetection capabilities. Photodetectors, as important components of sensing, imaging and communication systems, are able to perceive and convert optical signals to electrical signals. Herein, the large-area and high-quality lateral monolayer MoS2/WS2 heterojunctions were synthesized via the one-step liquid-phase chemical vapor deposition approach. Systematic characterization measurements have verified good uniformity and sharp interfaces of the channel materials. As a result, the photodetectors enhanced by the photogating effect can deliver competitive performance, including responsivity of ~ 567.6 A/W and detectivity of ~ 7.17 × 1011 Jones. In addition, the 1/f noise obtained from the current power spectrum is not conductive to the development of photodetectors, which is considered as originating from charge carrier trapping/detrapping. Therefore, this work may contribute to efficient optoelectronic devices based on lateral monolayer TMD heterostructures.

scholarly journals Site-Specific Electrodeposition Enables Self-Terminating Growth of Atomically Dispersed Metal Catalysts

2020 ◽  
Author(s):  
Yi Shi ◽  
Wenmao Huang ◽  
Jian Li ◽  
Yue Zhou ◽  
Zhongqiu Li ◽  
...  
Keyword(s):  
Large Scale ◽  
Transition Metal Dichalcogenides ◽  
Metal Catalysts ◽  
Atomic Scale ◽  
Single Atom ◽  
Scale Production ◽  
Heterogenous Catalysis ◽  
Site Specific ◽  
Metal Support ◽  
Metal Dichalcogenides

<p>The growth of atomically dispersed metal catalysts (ADMCs) remains a great challenge owing to the thermodynamically driven atom aggregation. Here we report a surface-limited electrodeposition technique that uses site-specific substrates for the rapid and room-temperature synthesis of ADMCs. We obtained ADMCs by the underpotential deposition (UPD) of a single-atom nonnoble metal onto the chalcogen atoms of chemically exfoliated transition metal dichalcogenides and subsequent galvanic displacement with a more-noble single-atom metal. The site-specific electrodeposition (SSED) enables the formation of energetically favorable metal–support bonds, and then automatically terminates the sequential formation of metallic bonding. The self-terminating effect restricts the metal deposition to the atomic scale. The modulated ADMCs exhibit remarkable activity and stability in the hydrogen evolution reaction compared to state-of-the-art single-atom electrocatalysts. We demonstrate that this SSED methodology could be extended to the synthesis of a variety of ADMCs (for example, Pt, Pd, Rh, Cu, Pb, Bi, and Sn single atoms), showing its general scope for the large-scale production of functional ADMCs in heterogenous catalysis. </p>

scholarly journals Site-Specific Electrodeposition Enables Self-Terminating Growth of Atomically Dispersed Metal Catalysts

2020 ◽  
Author(s):  
Yi Shi ◽  
Wenmao Huang ◽  
Jian Li ◽  
Yue Zhou ◽  
Zhongqiu Li ◽  
...  
Keyword(s):  
Large Scale ◽  
Transition Metal Dichalcogenides ◽  
Metal Catalysts ◽  
Atomic Scale ◽  
Single Atom ◽  
Scale Production ◽  
Heterogenous Catalysis ◽  
Site Specific ◽  
Metal Support ◽  
Metal Dichalcogenides

<p>The growth of atomically dispersed metal catalysts (ADMCs) remains a great challenge owing to the thermodynamically driven atom aggregation. Here we report a surface-limited electrodeposition technique that uses site-specific substrates for the rapid and room-temperature synthesis of ADMCs. We obtained ADMCs by the underpotential deposition (UPD) of a single-atom nonnoble metal onto the chalcogen atoms of chemically exfoliated transition metal dichalcogenides and subsequent galvanic displacement with a more-noble single-atom metal. The site-specific electrodeposition (SSED) enables the formation of energetically favorable metal–support bonds, and then automatically terminates the sequential formation of metallic bonding. The self-terminating effect restricts the metal deposition to the atomic scale. The modulated ADMCs exhibit remarkable activity and stability in the hydrogen evolution reaction compared to state-of-the-art single-atom electrocatalysts. We demonstrate that this SSED methodology could be extended to the synthesis of a variety of ADMCs (for example, Pt, Pd, Rh, Cu, Pb, Bi, and Sn single atoms), showing its general scope for the large-scale production of functional ADMCs in heterogenous catalysis. </p>

Intriguing electronic structures and optical properties of two-dimensional van der Waals heterostructures of Zr2CT2 (T = O, F) with MoSe2 and WSe2

2018 ◽  
Vol 6 (11) ◽  
pp. 2830-2839 ◽  
Author(s):  
Gul Rehman ◽  
S. A. Khan ◽  
B. Amin ◽  
Iftikhar Ahmad ◽  
Li-Yong Gan ◽  
...  
Keyword(s):  
Optical Properties ◽  
Material Properties ◽  
First Principles ◽  
Electronic Structures ◽  
Van Der Waals ◽  
Transition Metal Dichalcogenides ◽  
Two Dimensional ◽  
First Principles Calculations ◽  
Van Der Waals Heterostructures ◽  
Metal Dichalcogenides

Based on (hybrid) first-principles calculations, material properties (structural, electronic, vibrational, optical, and photocatalytic) of van der Waals heterostructures and their corresponding monolayers (transition metal dichalcogenides and MXenes) are investigated.

scholarly journals An emerging Janus MoSeTe material for potential applications in optoelectronic devices

2019 ◽  
Vol 7 (39) ◽  
pp. 12312-12320 ◽  
Author(s):  
Xiaoyong Yang ◽  
Deobrat Singh ◽  
Zhitong Xu ◽  
Ziwei Wang ◽  
Rajeev Ahuja
Keyword(s):  
First Principles ◽  
Transition Metal Dichalcogenides ◽  
Chemical Properties ◽  
Detailed Comparison ◽  
Physical And Chemical Properties ◽  
First Principles Calculations ◽  
Potential Applications ◽  
Metal Dichalcogenides ◽  
Physical And Chemical ◽  
And Chemical Properties

Motivated by the extraordinary physical and chemical properties of Janus transition-metal dichalcogenides (TMDs) due to the change of the crystal field originating from their asymmetry structures, the electronic and optical properties of the MoSeTe monolayer in 2H and 1T phases are systematically studied by first-principles calculations, and a detailed comparison with the parental MoSe2 and MoTe2 monolayer is made.

Atomic-Scale Chemical Conversion of Single-Layer Transition Metal Dichalcogenides

ACS Nano ◽  
2019 ◽  
Vol 13 (5) ◽  
pp. 5611-5615
Author(s):  
Peng Chen ◽  
Yun-Ting Chen ◽  
Ro-Ya Liu ◽  
Han-De Chen ◽  
Dengsung Lin ◽  
...  
Keyword(s):  
Transition Metal ◽  
Transition Metal Dichalcogenides ◽  
Single Layer ◽  
Chemical Conversion ◽  
Atomic Scale ◽  
Layer Transition ◽  
Metal Dichalcogenides
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