scholarly journals Enhanced thermoelectric efficiency in ferromagnetic silicene nanoribbons terminated with hydrogen atoms

2014 ◽  
Vol 16 (25) ◽  
pp. 12900-12908 ◽  
Author(s):  
K. Zberecki ◽  
R. Swirkowicz ◽  
M. Wierzbicki ◽  
J. Barnaś
Keyword(s):  
Ab Initio ◽  
Thermoelectric Properties ◽  
Thermoelectric Efficiency ◽  
Hydrogen Atoms ◽  
Silicene Nanoribbons

Using ab initio methods we calculate thermoelectric and spin thermoelectric properties of silicene nanoribbons with bare, mono-hydrogenated and di-hydrogenated edges.

scholarly journals Investigation of Effect of Pore Shape, Position and Passivation on the Thermoelectric Properties of Porous Armchair Silicene Nanoribbons

2019 ◽  
Vol 8 (3) ◽  
pp. 25-31
Author(s):  
Rajneesh Kumari ◽  
Deep Kamal Kaur Randhawa ◽  
Sukhdeep Kaur
Keyword(s):  
Thermoelectric Properties ◽  
Ballistic Transport ◽  
Empirical Method ◽  
Basis Set ◽  
Effect Of Temperature ◽  
Pore Shape ◽  
Thermoelectric Efficiency ◽  
Silicene Nanoribbons ◽  
Semi Empirical ◽  
Brenner Potential

In this paper, thermoelectric properties of porous armchair silicene nanoribbons (ASiNRs) have been investigated as a function of pore shape, position and passivation using the Non-equilibrium Green’s function (NEGF) method and Extended Huckel Technique (EHT). Here, nanopores of circular, rectangular, rhombus and triangular nature at different positions have been incorporated with an intention to optimize the structure for maximum thermoelectric figure of merit. In addition, the effect of passivation of the pore edges on the thermoelectric performance has been studied for all the shapes. Further, the effect of temperature variation on the thermoelectric efficiency has been studied. Ballistic transport regime and semi-empirical method using Huckel basis set are used to obtain the electrical properties, while the Brenner potential is used for the phononic system.

scholarly journals Enhanced Thermoelectric Properties of Armchair Graphene Nanoribbons with Pore Passivation

2018 ◽  
Vol 7 (2) ◽  
pp. 149-153
Author(s):  
Sukhdeep Kaur ◽  
Deep Kamal Kaur Randhawa ◽  
Sukhleen Bindra Narang
Keyword(s):  
Thermoelectric Properties ◽  
Waste Heat ◽  
Graphene Nanoribbons ◽  
Ballistic Transport ◽  
Thermoelectric Efficiency ◽  
Hydrogen Atoms ◽  
Armchair Graphene Nanoribbons ◽  
Semi Empirical ◽  
Thermoelectric Parameters ◽  
Armchair Graphene

There is a need to discover efficient thermoelectric materials that can generate electricity from waste heat and could play an important role in a global sustainable energy solution. Graphene Nanoribbons have been explored for a range of pore dimensions in order to achieve better thermoelectric performance. In this paper, we investigate the thermoelectric properties of porous armchair graphene nanoribbons by introducing hydrogen atoms as passivators at the pore surfaces. The aim of this work is to study the influence of pore passivation on the thermoelectric parameters as a function of pore geometry so as to open the possibility for an optimal pore engineering which can significantly improve the thermoelectric efficiency. The results show that the phonon thermal conductivity has a very little dependence on the pore edge passivation. An improvement in thermoelectric figure of merit is achieved due to the increased values of the power factor with consistent values of thermalconductivity. The unique thermoelectric properties of graphene nanoribbons with pore passivation suggest their great potentials for nanoscale thermoelectric applications. Within ballistic transport regime, semi-empirical extended Huckel method has been used for electrical properties while Tersoff potential has been employed for phononic calculations.

Formation of surface layer of hydrogen in pure aluminum

2019 ◽  
Vol 484 (1) ◽  
pp. 56-60
Author(s):  
D. A. Indejtsev ◽  
E. V. Osipova
Keyword(s):  
Surface Layer ◽  
Hydrogen Atom ◽  
Ab Initio ◽  
Pure Aluminum ◽  
Hydrogen Atoms ◽  
Energy Characteristics ◽  
Aluminum Crystal

Hydrogen atom behavior in pure aluminum is described by ab initio modelling. All main energy characteristics of the system consisting of hydrogen atoms in a periodic aluminum crystal are found.

Ab Initio Determination of a New Complex Structure (55 Non-Hydrogen Atoms) from Synchrotron Powder Data: An Uncommon Nickel Succinate, Ni7(C4H4O4)4(OH)6(H2O)3•7H2O

2004 ◽  
Vol 443-444 ◽  
pp. 333-336
Author(s):  
N. Guillou ◽  
C. Livage ◽  
W. van Beek ◽  
G. Férey
Keyword(s):  
Ab Initio ◽  
Complex Structure ◽  
Three Dimensional ◽  
Free Water ◽  
Hydrogen Atoms ◽  
Monoclinic System ◽  
Synchrotron Powder Diffraction ◽  
Chloride Hexahydrate ◽  
Autogenous Pressure

Ni7(C4H4O4)4(OH)6(H2O)3. 7H2O, a new layered nickel(II) succinate, was prepared hydrothermally (180°C, 48 h, autogenous pressure) from a 1:1.5:4.1:120 mixture of nickel (II) chloride hexahydrate, succinic acid, potassium hydroxide and water. It crystallizes in the monoclinic system (space group P21/c, Z = 4) with the following parameters a = 7.8597(1) Å, b = 18.8154(3)Å, c = 23.4377(4) Å,ϐ = 92.0288(9)°, and V = 3463.9(2) Å3. Its structure, which contains 55 non-hydrogen atoms, was solved ab initio from synchrotron powder diffraction data. It can be described from hybrid organic-inorganic layers, constructed from nickel oxide corrugated chains. These chains are built up from NiO6hexameric units connected via a seventh octahedron. Half of the succinates decorate the chains, and the others connect them to form the layers. The three dimensional arrangement is ensured by hydrogen bonds directly between two adjacent layers and via free water molecules.

Hydrogenated Amorphous Silicon Nitride: Structural and Electronic Properties

1998 ◽  
Vol 538 ◽  
Author(s):  
J. F. Justo ◽  
F. De Brito Mota ◽  
A. Fazziom
Keyword(s):  
Silicon Nitride ◽  
Ab Initio ◽  
Amorphous Silicon ◽  
Electronic Properties ◽  
Interatomic Potential ◽  
Hydrogen Atoms ◽  
Hydrogen Incorporation ◽  
Amorphous Silicon Nitride ◽  
Structural And Electronic Properties ◽  
Hydrogenated Amorphous

AbstractWe combined empirical and ab initio methods to study structural and electronic properties of amorphous silicon nitride. For such study, we developed an interatomic potential to describe the interactions between silicon, nitrogen, and hydrogen atoms. Using this potential, we performed Monte Carlo simulations in a simulated annealing scheme to study structural properties of amorphous silicon nitride. Then this potential was used to generate relevant structures of a-SiNx:Hy which were input configurations to ab initio calculations. We investigated the electronic and structural role played by hydrogen incorporation in amorphous silicon nitride.

scholarly journals Dumbbell configuration of silicon adatom defects on silicene nanoribbons

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Huynh Anh Huy ◽  
Quoc Duy Ho ◽  
Truong Quoc Tuan ◽  
Ong Kim Le ◽  
Nguyen Le Hoai Phuong
Keyword(s):  
Magnetic Properties ◽  
Band Gap ◽  
Density Functional ◽  
Spin Moment ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Electronic And Magnetic Properties ◽  
Spin Degeneracy ◽  
Silicene Nanoribbons ◽  
Formation Energies

AbstractUsing density functional theory (DFT), we performed theoretical investigation on structural, energetic, electronic, and magnetic properties of pure armchair silicene nanoribbons with edges terminated with hydrogen atoms (ASiNRs:H), and the absorptions of silicon (Si) atom(s) on the top of ASiNRs:H. The calculated results show that Si atoms prefer to adsorb on the top site of ASiNRs:H and form the single- and/or di-adatom defects depending on the numbers. Si absorption defect(s) change electronic and magnetic properties of ASiNRs:H. Depending on the adsorption site the band gap of ASiNRs:H can be larger or smaller. The largest band gap of 1 Si atom adsorption is 0.64 eV at site 3, the adsorption of 2 Si atoms has the largest band gap of 0.44 eV at site 1-D, while the adsorption at sites5 and 1-E turn into metallic. The formation energies of Si adsorption show that adatom defects in ASiNRs:H are more preferable than pure ASiNRs:H with silicon atom(s). 1 Si adsorption prefers to be added on the top site of a Si atom and form a single-adatom defect, while Si di-adatom defect has lower formation energy than the single-adatom and the most energetically favorable adsorption is at site 1-F. Si adsorption atoms break spin-degeneracy of ASiNRs:H lead to di-adatom defect at site 1-G has the highest spin moment. Our results suggest new ways to engineer the band gap and magnetic properties silicene materials.

scholarly journals Toward fully quantum modelling of ultrafast photodissociation imaging experiments. Treating tunnelling in the ab initio multiple cloning approach

2016 ◽  
Vol 194 ◽  
pp. 81-94 ◽  
Author(s):  
Dmitry V. Makhov ◽  
Todd J. Martinez ◽  
Dmitrii V. Shalashilin
Keyword(s):  
Kinetic Energy ◽  
Ab Initio ◽  
Energy Release ◽  
Kinetic Energy Release ◽  
Total Kinetic Energy ◽  
Recent Effort ◽  
Experimental Measurements ◽  
Quantum Level ◽  
Hydrogen Atoms ◽  
Quantum Simulations

We present an account of our recent effort to improve simulation of the photodissociation of small heteroaromatic molecules using the Ab Initio Multiple Cloning (AIMC) algorithm. The ultimate goal is to create a quantitative and converged technique for fully quantum simulations which treats both electrons and nuclei on a fully quantum level. We calculate and analyse the total kinetic energy release (TKER) spectra and Velocity Map Images (VMI), and compare the results directly with experimental measurements. In this work, we perform new extensive calculations using an improved AIMC algorithm that now takes into account the tunnelling of hydrogen atoms. This can play an extremely important role in photodissociation dynamics.

Thermoelectric properties of armchair and zigzag silicene nanoribbons

2012 ◽  
Vol 14 (39) ◽  
pp. 13588 ◽  
Author(s):  
L. Pan ◽  
H. J. Liu ◽  
X. J. Tan ◽  
H. Y. Lv ◽  
J. Shi ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Silicene Nanoribbons

Electronic, optical and thermoelectric properties of novel two-dimensional SbXY (X=Se, Te; Y=Br, I) family: ab initio perspective

2021 ◽  
Author(s):  
Asadollah Bafekry ◽  
M. Faraji ◽  
Mohamed Fadlallah ◽  
Hoat Do Minh ◽  
Hamad R. Jappor ◽  
...  
Keyword(s):  
Ab Initio ◽  
Thermoelectric Properties ◽  
Atomic Structure ◽  
Two Dimensional ◽  
Recent Developments

Recent developments in the synthesis of highly crystalline ultrathin BiTeX (X= Br, Cl) structures [Debarati Hajra et al., ACS Nano 14, 15626 (2020)] have led to exploring the atomic structure,...

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