scholarly journals Ab initiomodeling of the two-dimensional energy landscape of screw dislocations in bcc transition metals

2014 ◽  
Vol 89 (2) ◽  
Author(s):  
L. Dezerald ◽  
Lisa Ventelon ◽  
E. Clouet ◽  
C. Denoual ◽  
D. Rodney ◽  
...  
Keyword(s):  
Transition Metals ◽  
Energy Landscape ◽  
Two Dimensional ◽  
Screw Dislocations

Electronic properties of quasi two-dimensional transition metals chalcogenides with low-dimensional magnetism

Doklady BGUIR ◽  
2020 ◽  
Vol 18 (7) ◽  
pp. 87-95
Author(s):  
M. S. Baranava ◽  
P. A. Praskurava
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Exchange Interaction ◽  
Electronic Properties ◽  
Metal Atom ◽  
Transition Metal Atom ◽  
Two Dimensional ◽  
Transition Metal Atoms ◽  
Ground Magnetic ◽  
Low Dimensional

The search for fundamental physical laws which lead to stable high-temperature ferromagnetism is an urgent task. In addition to the already synthesized two-dimensional materials, there remains a wide list of possible structures, the stability of which is predicted theoretically. The article suggests the results of studying the electronic properties of MAX3 (M = Cr, Fe, A = Ge, Si, X = S, Se, Te) transition metals based compounds with nanostructured magnetism. The research was carried out using quantum mechanical simulation in specialized VASP software and calculations within the Heisenberg model. The ground magnetic states of twodimensional MAX3 and the corresponding energy band structures are determined. We found that among the systems under study, CrGeTe3 is a semiconductor nanosized ferromagnet. In addition, one is a semiconductor with a bandgap of 0.35 eV. Other materials are antiferromagnetic. The magnetic moment in MAX3 is localized on the transition metal atoms: in particular, the main one on the d-orbital of the transition metal atom (and only a small part on the p-orbital of the chalcogen). For CrGeTe3, the exchange interaction integral is calculated. The mechanisms of the formation of magnetic order was established. According to the obtained exchange interaction integrals, a strong ferromagnetic order is formed in the semiconductor plane. The distribution of the projection density of electronic states indicates hybridization between the d-orbital of the transition metal atom and the p-orbital of the chalcogen. The study revealed that the exchange interaction by the mechanism of superexchange is more probabilistic.

Integrated Origami-String System

2019 ◽  
Author(s):  
Ke Liu ◽  
Madelyn Kosednar ◽  
Tomohiro Tachi ◽  
Glaucio H. Paulino
Keyword(s):  
Mechanical Behavior ◽  
Design Space ◽  
Energy Landscape ◽  
Mechanical Systems ◽  
Two Dimensional ◽  
Structural System ◽  
One Dimensional ◽  
Elastic Strings ◽  
Paper Folding

Abstract Origami-inspired mechanical systems are mostly composed of two-dimensional elements, a feature inherited from paper folding. However, do we have to comply with this restriction on our design space? Would it be more approachable to achieve desired performance by integrating elements of different abstract dimensions? In this paper, we propose an integrated structural system consisting of both two-dimensional and one-dimensional elements. We attach elastic strings onto an origami design to modify its mechanical behavior and create new features. We show that, by introducing elastic strings to the recently proposed Morph pattern, we can obtain bistable units with programmable energy landscape. The behavior of this integrated origami-string system can be described by an elegant formulation, which can be used to explore its rich programmability.

scholarly journals Ab initio nanofluidics: disentangling the role of the energy landscape and of density correlations on liquid/solid friction

Nanoscale ◽  
2020 ◽  
Vol 12 (20) ◽  
pp. 10994-11000
Author(s):  
Gabriele Tocci ◽  
Maria Bilichenko ◽  
Laurent Joly ◽  
Marcella Iannuzzi
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Energy Landscape ◽  
Two Dimensional ◽  
Two Dimensional Materials ◽  
Order Of Magnitude ◽  
Solid Friction ◽  
Density Correlations

Ab initio molecular dynamics reveals that subtle variations in the energy landscape and density correlations can change by up to one order of magnitude the slippage of water on two-dimensional materials.

scholarly journals Catalysis Mediated by 2D Black Phosphorus Either Pristine or Decorated with Transition Metals Species

Surfaces ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 132-167
Author(s):  
Matteo Vanni ◽  
Maria Caporali ◽  
Manuel Serrano-Ruiz ◽  
Maurizio Peruzzini
Keyword(s):  
Catalytic Activity ◽  
Transition Metals ◽  
Visible Light Irradiation ◽  
2D Materials ◽  
Chemical Processes ◽  
Great Promise ◽  
The Novel ◽  
Two Dimensional ◽  
Basic Character ◽  
Selection Of

Among the novel class of mono-elemental two-dimensional (2D) materials, termed Xenes, phosphorene is emerging as a great promise for its peculiar chemical and physical properties. This review collects a selection of the recent breakthroughs that are related to the application of phosphorene in catalysis and electrocatalysis. Noteworthy, thanks to its intrinsic Lewis basic character, pristine phosphorene turned out to be more efficient and more selective than other non-metal catalysts, in chemical processes as the electroreduction of nitrogen to ammonia or the alkylation of nucleophiles with esters. Once functionalized with transition metals nanoparticles (Co, Ni, Pd, Pt, Ag, Au), its catalytic activity has been evaluated in several processes, mainly hydrogen and oxygen evolution reactions. Under visible light irradiation, it has shown a great improvement of the activity, demonstrating high potential as a photocatalyst.

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