scholarly journals Atomic Vacancy Defect, Frenkel Defect and Transition Metals (Sc, V, Zr) Doping in Ti4N3 MXene Nanosheet: A First-Principles Investigation

2020 ◽  
Vol 10 (7) ◽  
pp. 2450
Author(s):  
Tingyan Zhou ◽  
Wan Zhao ◽  
Kun Yang ◽  
Qian Yao ◽  
Yangjun Li ◽  
...  
Keyword(s):  
Transition Metal ◽  
High Spin ◽  
First Principles ◽  
Density Functional ◽  
Vacancy Defect ◽  
Potential Candidate ◽  
Magnetic Exchange ◽  
Type Defect ◽  
Spin Polarizability ◽  
Atomic Vacancy

Using first-principles calculations based on the density functional theory, the effects of atomic vacancy defect, Frenkel-type defect and transition metal Z (Z = Sc, V and Zr) doping on magnetic and electric properties of the Ti4N3 MXene nanosheet were investigated comprehensively. The surface Ti and subsurface N atomic vacancies are both energetically stable based on the calculated binding energy and formation energy. In addition, the former appears easier than the latter. They can both enhance the magnetism of the Ti4N3 nanosheet. For atom-swapped disordering, the surface Ti-N swapped disordering is unstable, and then the Frenkel-type defect will happen. In the Frenkel-type defect system, the total magnetic moment decreases due to the enhancement of indirect magnetic exchange between surface Ti atoms bridged by the N atom. A relatively high spin polarizability of approximately 70% was detected. Furthermore, the doping effects of transition metal Z (Z = Sc, V and Zr) on Ti4N3 nanosheet are explored. All doped systems are structurally stable and have relatively large magnetism, which is mainly induced by the directed magnetic exchange between surface Z and Ti atoms. Especially in the doped Ti4N3-Sc system, the high spin polarizability is still reserved, suggesting that this doped system can be a potential candidate for application in spintronics.

Flexoelectricity in atomic monolayers from first principles

Nanoscale ◽  
2020 ◽  
Author(s):  
Shashikant Kumar ◽  
David Codony ◽  
Irene Arias ◽  
Phanish Suryanarayana
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Ab Initio ◽  
First Principles ◽  
Density Functional ◽  
Transition Metal Dichalcogenides ◽  
Functional Theory ◽  
Group Iii ◽  
Flexoelectric Effect ◽  
Metal Dichalcogenides

We study the flexoelectric effect in fifty-four select atomic monolayers using ab initio Density Functional Theory (DFT). Specifically, considering representative materials from each of Group III monochalcogenides, transition metal dichalcogenides...

Oxygen-evolution reactions (OER) on transition-metal-doped Fe3Co(PO4)4 iron-phosphate surfaces: a first-principles study

2021 ◽  
Author(s):  
Yogeshwaran Krishnan ◽  
Sateesh Bandaru ◽  
Niall J. English
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Oxygen Evolution ◽  
First Principles ◽  
Density Functional ◽  
Iron Phosphate ◽  
Functional Theory ◽  
First Principles Study ◽  
Metal Doped ◽  
Catalyst Surfaces

A series of transition-metal-doped Fe1−xMxCo(PO4)4(010) and Fe3Co1−xMx(PO4)4(010) electro-catalyst surfaces (with M = Mn, Os, Ru, Rh and Ir) have been modelled via density-functional theory (DFT) to gauge their oxygen-evolution reactions (OER).

scholarly journals Oxygen Vacancy Induced Magnetism in Anti-Perovskite Topological Dirac Semimetal Ba3SnO

2021 ◽  
Author(s):  
Javaria Batool ◽  
Syed Muhammad Alay-e-Abbas ◽  
Gustav Johansson ◽  
Waqas Zulfiqar ◽  
Muhammad Arsam Danish ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Oxygen Vacancy ◽  
Electronic Properties ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Vacancy Defect ◽  
Functional Theory ◽  
Dirac Semimetal

The thermodynamic, structural, magnetic and electronic properties of pristine and intrinsic vacancy defect containing topological Dirac semimetal Ba3SnO are studied using first-principles density functional theory calculations. The thermodynamic stability of...

First-Principles Study of Interaction of Lithium Atoms with (3, 3) Carbon Nanotubes

2014 ◽  
Vol 687-691 ◽  
pp. 4311-4314 ◽  
Author(s):  
Shun Fu Xu ◽  
Ling Min Li
Keyword(s):  
Carbon Nanotubes ◽  
First Principles ◽  
Density Functional ◽  
Vacancy Defect ◽  
Single Wall Carbon Nanotubes ◽  
Generalized Gradient ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Vacancy Defects ◽  
Adsorption Mechanisms

In this paper, we have employed first-principles calculations to investigate the adsorption mechanisms of one lithium atom on the sidewalls of 1/2/3 H-adsorbed indefective/defective (3, 3) single-wall carbon nanotubes (CNTs) which have vacancy defects. Our calculations are performed within density functional theory (DFT) under the generalized gradient approximation (GGA) of Perdew, Burke, and Ernzerhof (PBE).Our results show that the lithium atoms strongly binds to the H-adsorbed (3, 3) nanotube. Lithium atoms can chemically adsorb on (3, 3) nanotube with the vacancy defect (MVD) without any energy barrier. The lithium adsorption will enhance the electrical conductivity of the nanotube. Further more, the structure of the (3, 3) nanotube with the MVD and hydrogen atoms will become more stable after the three kinds of lithium adsorption.

A computational study of hydrogen doping induced metal-to-insulator transition in CaFeO3, SrFeO3, BaFeO3 and SmMnO3

2019 ◽  
Vol 21 (45) ◽  
pp. 25397-25405
Author(s):  
Shukai Yao ◽  
Pilsun Yoo ◽  
Peilin Liao
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
First Principles ◽  
Density Functional ◽  
Computational Study ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Hydrogen Doping ◽  
Gap Opening ◽  
Metal To Insulator Transition

First principles density functional theory calculations were performed to identify transition metal perovskites CaFeO3, SrFeO3, BaFeO3 and SmMnO3 as promising candidates with large band gap opening upon hydrogen doping.

scholarly journals Screening for high-spin metal organic frameworks (MOFs): density functional theory study on DUT-8(M1,M2) (with Mi = V,…,Cu)

2016 ◽  
Vol 18 (11) ◽  
pp. 8075-8080 ◽  
Author(s):  
Sebastian Schwalbe ◽  
Kai Trepte ◽  
Gotthard Seifert ◽  
Jens Kortus
Keyword(s):  
Density Functional Theory ◽  
High Spin ◽  
First Principles ◽  
Density Functional ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Metal Centers ◽  
Metal Organic

We present a first principles study of low-spin (LS)/high-spin (HS) screening for 3d metal centers in the metal organic framework (MOF) DUT-8(Ni).

scholarly journals ELASTIC PROPERTIES OF TRANSITION METAL DIOXIDES: XO2 (X = Ru, Rh, Os, andIr)

2008 ◽  
Vol 19 (08) ◽  
pp. 1269-1275 ◽  
Author(s):  
YANLING LI ◽  
ZHI ZENG
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Shear Modulus ◽  
Elastic Properties ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Debye Temperatures ◽  
Metal Dioxides

The elastic properties of rutile transition metal dioxides XO2 ( X = Ru , Rh , Os , and Ir ) are investigated using first-principles calculations based on density functional theory. Elastic constants, bulk modulus, shear modulus, and Young's modulus as well as Possion ratio are given. OsO 2 and IrO 2 show strong incompressibility. The hardness estimated for these dioxides shows that they are not superhard solids. The obtained Debye temperatures are comparative to those of transition metal dinitrides or diborides.

First-principles study of optical properties in Ca-doped ZnO alloys

Open Physics ◽  
2012 ◽  
Vol 10 (5) ◽  
Author(s):  
Li-Na Bai ◽  
Jian-She Lian ◽  
Wei-Tao Zheng ◽  
Qing Jiang
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Optical Transition ◽  
High Energy ◽  
Ternary Alloys ◽  
Potential Candidate ◽  
Coulomb Interactions ◽  
Generalized Gradient ◽  
Light Emitters

AbstractVarious electronic and optical properties of Zn1−x CaxO ternary alloys of wurtzite structure are calculated using a first-principles approach based on the framework of the generalized gradient approximation to density-functional theory. In particular, on-site Coulomb interactions are introduced, which can reasonably well predict the electronic properties and band gaps of the Zn1−x CaxO (0≤x≤0.25) system. The imaginary part of the calculated dielectric function indicates that the optical transition between O 2p states in the valence band and Zn 4s states in the conduction band shifts to the high-energy range as the Ca concentration increases. The calculated band gap shows a significant increase with increasing Ca concentration. Therefore, Zn1−x CaxO ternary alloys may be a potential candidate alloy for optoelectronic materials, and especially for light-emitters and detectors.

scholarly journals First-Principles Calculation of Transition Metal Hyperfine Coupling Constants with the Strongly Constrained and Appropriately Normed (SCAN) Density Functional and its Hybrid Variants

2019 ◽  
Vol 5 (4) ◽  
pp. 69 ◽  
Author(s):  
Dimitrios A. Pantazis
Keyword(s):  
Transition Metal ◽  
First Principles ◽  
Density Functional ◽  
Hyperfine Coupling ◽  
Coupling Constants ◽  
First Principles Calculation ◽  
Chemical System ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Hyperfine Coupling Constants

Density functional theory (DFT) is used extensively for the first-principles calculation of hyperfine coupling constants in both main-group and transition metal systems. As with many other properties, the performance of DFT for hyperfine coupling constants is of variable quality, particularly for transition metal complexes, because it strongly depends on the nature of the chemical system and the type of approximation to the exchange-correlation functional. Recently, a meta-generalized-gradient approximation (mGGA) functional was proposed that obeys all known exact constraints for such a method, known as the Strongly Constrained and Appropriately Normed (SCAN) functional. In view of its theoretically superior formulation a benchmark set of complexes is used to assess the performance of SCAN for the challenging case of transition metal hyperfine coupling constants. In addition, two global hybrid versions of the functional, SCANh and SCAN0, are described and tested. The values computed with the new functionals are compared with experiment and with those of other DFT approximations. Although the original SCAN and the SCAN-based hybrids may offer improved hyperfine coupling constants for specific systems, no uniform improvement is observed. On the contrary, there are specific cases where the new functionals fail badly due to a flawed description of the underlying electronic structure. Therefore, despite these methodological advances, systematically accurate and system-independent prediction of transition metal hyperfine coupling constants with DFT remains an unmet challenge.

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