Vacancy-Induced Magnetism in Fluorographene: The Effect of Midgap State

Based on density functional theory, we have systematically investigated the geometric, magnetic, and electronic properties of fluorographene with three types of vacancy defects. With uneven sublattice, the partial defect structures are significantly spin-polarized and present midgap electronic states. The magnetic moment is mainly contributed by the adjacent C atoms of vacancy defects. Furthermore, the strain dependence of the bandgap is analyzed and shows a linear trend with applied strain. This defect-induced tunable narrow bandgap material has great potential in electronic devices and spintronics applications.

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Momentum-dependent band spin splitting in semiconducting MnO2: a density functional calculation

Physical Chemistry Chemical Physics ◽

10.1039/c5cp07806g ◽

2016 ◽

Vol 18 (19) ◽

pp. 13294-13303 ◽

Cited By ~ 13

Author(s):

Yusuke Noda ◽

Kaoru Ohno ◽

Shinichiro Nakamura

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Manganese Oxides ◽

Electronic States ◽

Spin Splitting ◽

Density Functional Calculation ◽

Functional Theory ◽

Spin Polarized ◽

Crystal Phases ◽

The Relationship

The electronic states of pristine manganese dioxides in different crystal phases have been explored using spin-polarized density functional theory with Hubbard U correction to provide a basis to understand the relationship between the spin-dependent electronic states and the crystallography of manganese oxides.

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The Electronic and Magnetic Properties of Chemically Decorated Boron Nitride Sheet

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.130-134.1439 ◽

2011 ◽

Vol 130-134 ◽

pp. 1439-1443

Author(s):

Qing Zhou ◽

Wei Jiang ◽

An Long Kuang ◽

Hong Kuan Yuan ◽

Hong Chen

Keyword(s):

Magnetic Properties ◽

Boron Nitride ◽

Density Functional ◽

Electronic Devices ◽

Wide Band ◽

Functional Theory ◽

Half Metallic ◽

Electronic And Magnetic Properties ◽

Spin Polarized ◽

Magnetic Transfer

The electronic and magnetic properties of the boron nitride (BN) sheets with different chemical decoration are investigated using the first-principles plane-wave calculations within density functional theory (DFT). It is demonstrated that bare BN sheets are nonmagnetic semiconductors with wide band gaps, and a metallic–semiconducting–half-metallic transition with a nonmagnetic– magnetic transfer can be realized through chemical decoration. Specifically, BN sheets modified by H with zigzag configuration still behave as semiconductors, while with armchair configuration are metallic. Nevertheless, decorating BN sheets by F or OH with zigzag configuration reveal half-metallic properties, then with armchair configuration present spin-polarized semiconducting characteristics. The results may be of importance in designing BN-based electronic devices for nanoelectronic applications.

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Study on adsorption of CO and CO2 by graphene gas sensor

Modern Physics Letters B ◽

10.1142/s0217984921501542 ◽

2021 ◽

pp. 2150154

Author(s):

Wenchao Tian ◽

Jiahao Niu ◽

Wenhua Li ◽

Xiaohan Liu

Keyword(s):

Gas Sensors ◽

Active Sites ◽

Density Functional ◽

Gas Adsorption ◽

Experimental Studies ◽

Detection Accuracy ◽

Functional Theory ◽

Vacancy Defects ◽

Adsorption Of Co ◽

Detection Characteristics

The two-dimensional (2D) plane of graphene has many active sites for gas adsorption. It has broad application prospects in the field of MEMS gas sensors. At present, there are many experimental studies on graphene gas sensors, but it is difficult to accurately control various influencing factors in the experiments. Therefore, this paper applies the first principle based on density functional theory to study the adsorption and detection characteristics of graphene on CO and CO2. The first-principles analysis method was used to study the adsorption characteristics and sensitivity of graphene. The results show that the inductive graphene has a sensitivity of 1.55% and 0.77% for CO and CO2, respectively. The Stone–Wales defects and multi-vacancy defects have greatly improved the sensitivity of graphene to CO, which is 35.25% and 4.14%, respectively. Introduction of defects increases the sensitivity of detection of CO and CO2, but also improves the selective gas detection material of these two gases. Thus, the control and selectively introducing defects may improve the detection accuracy of the graphene CO and CO2.

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Pd/Pt embedded CN monolayers as efficient catalysts for CO oxidation

Physical Chemistry Chemical Physics ◽

10.1039/c9cp04636d ◽

2019 ◽

Vol 21 (46) ◽

pp. 25743-25748

Author(s):

Yong-Chao Rao ◽

Xiang-Mei Duan

Keyword(s):

Density Functional Theory ◽

Co Oxidation ◽

Density Functional ◽

Carbon Nitride ◽

Density Functional Theory Calculations ◽

Catalytic Performance ◽

Functional Theory ◽

Spin Polarized ◽

Planar Carbon

The catalytic performance of Pd/Pt embedded planar carbon nitride for CO oxidation has been investigated via spin-polarized density functional theory calculations.

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Research Optical Characteristics of H2S Molecule Adsorption on Agn (n=2,4,6) Clusters

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.321-324.499 ◽

2013 ◽

Vol 321-324 ◽

pp. 499-502

Author(s):

Hong Zhou ◽

Jun Feng Wang ◽

Jun Qing Wen ◽

Wei Bin Cheng ◽

Jun Fei Wang

Keyword(s):

Density Functional Theory ◽

Infrared Spectrum ◽

Density Functional ◽

Global Minimum ◽

Electronic States ◽

Binding Energies ◽

Optical Characteristics ◽

Functional Theory ◽

Calculation Results ◽

Planar Geometries

Density-functional theory has been used to calculate the energetically global-minimum geometries and electronic states of AgnH2S (n=2, 4, 6) clusters. The lowest-energy structures of Ag2, Ag4, Ag6, Ag2H2S, Ag4H2S and Ag6H2S clusters were obtained, respectively. The calculation results show that the lowest-energy structures of Ag2, Ag4and Ag6clusters are planar geometries. The binding energies of Agn(n=2, 4, 6) clusters are gradually increasing in our calculations. Compare the infrared spectrum peaks of Ag4cluster with that of Ag6cluster, which show that the peaks shift to shortwave. After adsorption, we found that the peaks shift to shortwave by comparison.

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Local and electronic structure around Ga in CdTe: evidence of DX- and A-centers

Journal of Synchrotron Radiation ◽

10.1107/s0909049512042197 ◽

2012 ◽

Vol 20 (1) ◽

pp. 166-171

Author(s):

Vasil Koteski ◽

Jelena Belošević-Čavor ◽

Petro Fochuk ◽

Heinz-Eberhard Mahnke

Keyword(s):

Density Functional ◽

Plane Waves ◽

Lattice Relaxation ◽

Defect Structures ◽

Functional Theory ◽

Edge Structure ◽

X Ray ◽

First Time ◽

X Ray Absorption ◽

Good Agreement

The lattice relaxation around Ga in CdTe is investigated by means of extended X-ray absorption spectroscopy (EXAFS) and density functional theory (DFT) calculations using the linear augmented plane waves plus local orbitals (LAPW+lo) method. In addition to the substitutional position, the calculations are performed for DX- and A-centers of Ga in CdTe. The results of the calculations are in good agreement with the experimental data, as obtained from EXAFS and X-ray absorption near-edge structure (XANES). They allow the experimental identification of several defect structures in CdTe. In particular, direct experimental evidence for the existence of DX-centers in CdTe is provided, and for the first time the local bond lengths of this defect are measured directly.

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D–A–D-type narrow-bandgap small-molecule photovoltaic donors: pre-synthesis virtual screening using density functional theory

Physical Chemistry Chemical Physics ◽

10.1039/c5cp07536j ◽

2016 ◽

Vol 18 (22) ◽

pp. 15054-15059 ◽

Cited By ~ 9

Author(s):

Yeongrok Gim ◽

Daekyeom Kim ◽

Minkyu Kyeong ◽

Seunghwan Byun ◽

Yuri Park ◽

...

Keyword(s):

Density Functional Theory ◽

Virtual Screening ◽

Small Molecule ◽

Density Functional ◽

Density Functional Theory Calculations ◽

Time Dependent ◽

Functional Theory ◽

Narrow Bandgap ◽

Dependent Density

A new series of D–A–D-type small-molecule photovoltaic donors are designed and screened before synthesis using time-dependent density functional theory calculations.

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Effect of Point Defects on Electronic Properties and Structure of Talc (001) Surface by First Principles

Minerals ◽

10.3390/min12010069 ◽

2022 ◽

Vol 12 (1) ◽

pp. 69

Author(s):

Xindi Ma ◽

Huicong Du ◽

Ping Lan ◽

Jianhua Chen ◽

Lihong Lan

Keyword(s):

Electronic Properties ◽

Density Functional ◽

Surface States ◽

State Density ◽

Functional Theory ◽

Vacancy Defects ◽

Impurity Atoms ◽

Electron State Density ◽

Calculation Results ◽

Impurity Defects

The surface structure and electronic properties of Mg vacancy defects on talc (001) and impurity defects with Fe, Mn, Ni, Al, and Ca replacing Mg atoms were calculated by using density functional theory. The calculation results show that the order of impurity substitution energy is Mn < Ni < Al < Ca < Fe. This indicates that Fe impurity defects are most easily formed in talc crystals. The covalent bonding between Si atoms and reactive oxygen atoms adjacent to impurity atoms is weakened and the ionic property is enhanced. The addition of Fe, Mn, and Ni atoms makes the surface of talc change from an insulator to a semiconductor and enhances its electrical conductivity. The analysis of electron state density shows that surface states composed of impurity atoms 4S orbital appear near the Fermi level.

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Zn Doping Induced Band Gap Widening of Ag2O Nanoparticles

10.26434/chemrxiv.11105576 ◽

2019 ◽

Author(s):

Arup Kumar De ◽

Sourav Majumdar ◽

Shaili Pal ◽

Sunil Kumar ◽

Indrajit Sinha

Keyword(s):

Metal Ion ◽

Density Functional ◽

Density Functional Theory Calculations ◽

Mole Percent ◽

Functional Theory ◽

Ion Density ◽

Calculated Density ◽

Zn Doping ◽

Narrow Bandgap ◽

Ag2o Nanoparticles

Semiconductor bandgap widening is a little investigated phenomenon in photocatalysis literature. The present investigation attempts the widening of the narrow bandgap of Ag2O to make it a semiconductor with more attractive properties. The synthesis of Zn doped Ag2O nanostructures followed a typical hydrothermal synthesis procedure. An increase in the lattice parameters of Ag2O with doping indicated the occupation of an interstitial position by the dopant metal ion. Density functional theory calculations also demonstrated the expansion of the Ag2O crystal lattice with the dopant at an interstitial location. The bandgap of the Ag2O increased to 1.65 eV for 5-mole percent doping. The DFT calculated density of states (DOS) plots also exhibit an increase in the bandgap of Ag2O after Zn doping. These doped Ag2O nanoparticles were useful in photocatalysis of methyl orange degradation under visible light irradiation.

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