scholarly journals Investigation of the Effect of 3d TM-TM Atom Co-Doped in Graphene Nanosheet: DFT Based Calculations

2021 ◽  
pp. 122-132
Keyword(s):  
Magnetic Properties ◽  
Density Functional ◽  
Graphene Nanosheets ◽  
Single Point ◽  
Magnetic Behavior ◽  
Pristine Graphene ◽  
Graphene Nanosheet ◽  
Metallic Behavior ◽  
Doped Graphene ◽  
Co Doped

Graphene, an interesting 2D system has a rare electronic structure of two inverted Dirac cones touching at a single point, with great electron mobility and promising microelectronics applications. In the present article, a theoretical investigation has been performed on the structural, electronic, and magnetic properties of pristine graphene nanosheet and also the effect of 3d transition metal (TM) co-doped in graphene nanosheet within the density functional theory framework. 3d TM is categorized into two groups: Cr- group (Cr-Cr, Cr-Mn, and Cr-Fe) and Ni-group (Ni-Cr, Ni-Ti, Ni-Mn). After co-doping TM atoms on graphene, it still holds its planar shape which refers to the stability of these co-doped graphene nanosheets. This is also confirmed by the increasing bond length of carbon and TM atoms on graphene nanosheets. Highest zero-point energies have been found of -12049.24eV and -10936.87eV respectively for Cr-Cr and Ni-Cr co-doped graphene nanosheet. According to Mulliken's charge and electron density differences, all the TM atoms can act as electron donors while the graphene nanosheet is electron acceptor. All the TMs co-doped graphene nanosheet show metallic behavior in terms of band structures and DOS plots except Ti-Ni which has shown a little band gap. In terms of electronic properties, Cr-Cr and Ni-Cr co-doped graphene nanosheets are found most stable among the other studied systems and they can exhibit magnetic behavior as there is a variation in their up and down spin as shown in spin polarized DOS. That’s why they are beneficial to the application of various magnetic devices as well as sectors. Besides Cr-group co-doped graphene nanosheet can exhibit better magnetic properties than Ni-group.

A DFT Study of CO and NO Adsorptions on AlN-, AlP-, and ZnO-doped Graphene Nanosheets

2016 ◽  
Vol 230 (2) ◽  
Author(s):  
Niwat Promthong ◽  
Nadtanet Nunthaboot ◽  
Wanno Banchob
Keyword(s):  
Density Functional ◽  
Gas Adsorption ◽  
Graphene Nanosheets ◽  
Nitrogen Monoxide ◽  
Density Functional Theory Calculations ◽  
Pristine Graphene ◽  
Functional Theory ◽  
Co Doping ◽  
Doped Graphene ◽  
Co Doped

AbstractDensity functional theory calculations were performed to investigate the adsorption abilities of carbon monoxide (CO) and nitrogen monoxide (NO) gas molecules onto pristine graphene nanosheet (GNS), and AlN-, AlP-, and ZnO-doped GNSs. The co-doping of AlN, AlP, and ZnO onto GNS can improve the CO and NO adsorption abilities of GNS. The gas adsorption abilities on the pristine and co-doped GNSs were determined to be, in decreasing order: ZnO-GNS ∼ AlP-GNS > AlN-GNS > pristine GNSs and AlP-GNS > AlN-GNS > ZnO-GNS > pristine GNSs for the adsorptions of CO and NO, respectively. These newly developed co-doped GNSs could be candidates for CO and NO gas storages. The adsorption geometries, adsorption energies, density of states, and charge transfers were also reported.

scholarly journals The Adsorption Behavior of Gas Molecules on Co/N Co–Doped Graphene

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7700
Author(s):  
Tingyue Xie ◽  
Ping Wang ◽  
Cuifeng Tian ◽  
Guozheng Zhao ◽  
Jianfeng Jia ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Gas Sensor ◽  
Density Functional ◽  
Gas Adsorption ◽  
Adsorption Behavior ◽  
Spintronic Devices ◽  
So2 Adsorption ◽  
Doped Graphene ◽  
Gas Molecules ◽  
Co Doped

Herein, we have used density functional theory (DFT) to investigate the adsorption behavior of gas molecules on Co/N3 co–doped graphene (Co/N3–gra). We have investigated the geometric stability, electric properties, and magnetic properties comprehensively upon the interaction between Co/N3–gra and gas molecules. The binding energy of Co is −5.13 eV, which is big enough for application in gas adsorption. For the adsorption of C2H4, CO, NO2, and SO2 on Co/N–gra, the molecules may act as donors or acceptors of electrons, which can lead to charge transfer (range from 0.38 to 0.7 e) and eventually change the conductivity of Co/N–gra. The CO adsorbed Co/N3–gra complex exhibits a semiconductor property and the NO2/SO2 adsorption can regulate the magnetic properties of Co/N3–gra. Moreover, the Co/N3–gra system can be applied as a gas sensor of CO and SO2 with high stability. Thus, we assume that our results can pave the way for the further study of gas sensor and spintronic devices.

FIRST PRINCIPLES STUDY OF CYTOSINE ADSORPTION ON GRAPHENE

2009 ◽  
Vol 08 (01n02) ◽  
pp. 5-8 ◽  
Author(s):  
YONG-HUI ZHANG ◽  
KAI-GE ZHOU ◽  
KE-FENG XIE ◽  
CAI-HONG LIU ◽  
HAO-LI ZHANG ◽  
...  
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Binding Energies ◽  
Pristine Graphene ◽  
Functional Theory ◽  
Metal Atoms ◽  
Order Of Magnitude ◽  
Doped Graphene ◽  
Co Doped

The adsorption of cytosine on graphene surface is studied using density functional theory with local density approximation. The cytosine is physisorbed onto graphene through π–π interaction, with a binding energy around -0.39 eV. Due to the weak interaction, the electronic properties of graphene show little change upon adsorption. The cytosine/graphene interaction can be strongly enhanced by introducing metal atoms. The binding energies increase to -0.60 and -2.31 eV in the presence of Li and Co atoms, respectively. The transport behavior of an electric sensor based on Co -doped graphene shows a sensitivity one order of magnitude higher than that of a similar device using pristine graphene. This work reveals that the sensitivity of graphene-based bio-sensors could be drastically improved by introducing appropriate metal atoms.

scholarly journals Bandgap Engineering in Iron Doped Graphene Nanosheets: Electrical Performance Boosting for Application in Nano-electronics 

2020 ◽  
Author(s):  
Swarnava Biswas ◽  
Debajit Sen ◽  
Moumita Mukherjee
Keyword(s):  
Electrical Properties ◽  
Graphene Nanosheets ◽  
Electrical Performance ◽  
Pristine Graphene ◽  
Iron Doping ◽  
Bandgap Engineering ◽  
Graphene Nanosheet ◽  
Potential Measurement ◽  
Energy Value ◽  
Doped Graphene

The study reports electrical properties of iron atom doped graphene nanosheets using Atomistix Tool Kit- Virtual NanoLab (ATK-VNL) QuantumWise simulation package. Density Function Theory (DFT) has been adopted for the present study. The introduction of iron atoms in a bare graphene nanosheet make changes in the band-structure of otherwise perfectly overlapped bandgap of pristine graphene nanosheets. The controlled amount of iron doping opens a small bandgap in graphene and that enhances gradually with further increase of doping concentration. Chemical potential measurement indicates a steady increase in the magnitude from - 5.661314 eV to - 5.910896 eV. The study depicts that the pristine graphene nanosheet exhibits a DOS value of ~330 eV-1 at energy value ~12 eV, but in case of its doped counterpart, the DOS values change to ~290 eV-1, ~270 eV-1 and ~250 eV-1 respectively for one, two and three atoms doped graphene nanosheets at a specific energy value of ~12 eV. The paper will address the total energy and transmission spectrum of bare and doped graphene nanosheets. The role of iron dopant in tuning the electrical properties of graphene nanosheets are studied extensively for application in nano-electronics. To the best of authors knowledge this is the first report on bandgap engineering in graphene nanosheets by controlled iron doping.

scholarly journals Effect of the number of nitrogen dopants on the electronic and magnetic properties of graphitic and pyridinic N-doped graphene – a density-functional study

RSC Advances ◽  
2021 ◽  
Vol 11 (30) ◽  
pp. 18371-18380
Author(s):  
Erik Bhekti Yutomo ◽  
Fatimah Arofiati Noor ◽  
Toto Winata
Keyword(s):  
Magnetic Properties ◽  
Density Functional ◽  
Functional Study ◽  
Density Functional Study ◽  
Electronic And Magnetic Properties ◽  
Doped Graphene ◽  
Dopant Atoms ◽  
Pyridinic N

The number of dopant atoms is a parameter that can effectively tune the electronic and magnetic properties of graphitic and pyridinic N-doped graphene.

Electronic properties of N-rich graphene nano-chevrons.

2021 ◽  
Author(s):  
Anderson Soares da Costa Azevêdo ◽  
Aldilene Saraiva-Souza ◽  
Vincent Meunier ◽  
Eduardo Costa Girão
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Theoretical Analysis ◽  
Electronic Properties ◽  
Density Functional ◽  
Functional Theory ◽  
Nitrogen Doped ◽  
Electronic And Magnetic Properties ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

Theoretical analysis based on density functional theory is used to describe the microscopic origins of emerging electronic and magnetic properties in quasi-1D nitrogen-doped graphene nanoribbon structures with chevron-like (or wiggly-edged)...

Electronic Structure and Ferromagnetic Properties of Doped Calcium Sulfide Ca1−xTMxS (TM = V, Cr and Co)

SPIN ◽  
2020 ◽  
Vol 10 (02) ◽  
pp. 2050013 ◽  
Author(s):  
Amina Aiche ◽  
Abdelkader Tadjer ◽  
Hadj Moulay Ahmed Mazouz ◽  
Bendouma Doumi ◽  
Houari Khachai
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Density Functional ◽  
Double Exchange ◽  
Ferromagnetic State ◽  
Spin Splitting ◽  
Full Potential ◽  
Generalized Gradient ◽  
Metallic Behavior ◽  
Half Metallic

The electronic structure and magnetic properties of diluted Ca[Formula: see text]TMxS (TM[Formula: see text][Formula: see text][Formula: see text]V, Cr and Co) in the rocksalt structure at concentrations [Formula: see text], 0.125 and 0.25 were studied using the full-potential linearized augmented plane wave approximation of the density functional theory with the Wu-Cohen generalized gradient approximation (WC-GGA) and the Tran–Blaha-modified Becke–Johnson (TB-mBJ) potential. Features such as lattice constant, bulk modulus, spin-polarized band structures, total and local densities of states and magnetic properties have been computed. The electronic structure show that Ca[Formula: see text](V, Cr)xS at all the studied concentrations and the diluted Ca[Formula: see text]CoxS with [Formula: see text] compounds are half-metallic ferromagnets with spin polarization of 100%. The calculated total magnetic moments for Ca[Formula: see text]VxS and Ca[Formula: see text]CoxS show the same integer value of 3[Formula: see text][Formula: see text] per formula unit and Ca[Formula: see text]CrxS exhibit a total magnetic moment of 4[Formula: see text][Formula: see text], which confirm the half-metallic behavior of these compounds. We also calculated the values of the band edge spin splitting of the valence and conduction bands and the exchange constants. We have found that the ferromagnetic state is stable by the p-d exchange associated with the double-exchange mechanism. The diluted Ca[Formula: see text](V,Cr,Co)xS are found to be new promising candidates for spintronic applications.

scholarly journals CO Tolerance and Stability of Graphene and N-Doped Graphene Supported Pt Anode Electrocatalysts for Polymer Electrolyte Membrane Fuel Cells

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 597
Author(s):  
Martin González-Hernández ◽  
Ermete Antolini ◽  
Joelma Perez
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Graphene Nanosheets ◽  
Polymer Electrolyte Membrane ◽  
Co Adsorption ◽  
Active Surface Area ◽  
Pristine Graphene ◽  
Electrolyte Membrane ◽  
Co Tolerance ◽  
Doped Graphene

Pt electrocatalysts supported on pristine graphene nanosheets (GNS) and nitrogen-doped graphene nanoplatelets (N-GNP) were prepared through the ethylene glycol process, and a comparison of their CO tolerance and stability as anode materials in polymer electrolyte membrane fuel cells (PEMFCs) with those of the conventional carbon (C)-supported Pt was made. Repetitive potential cycling in a half cell showed that Pt/GNS catalysts have the highest stability, in terms of the highest sintering resistance (lowest particle growth) and the lowest electrochemically active surface area loss. By tests in PEMFCs, the Pt/N-GNP catalyst showed the highest CO tolerance, while the poisoning resistance of Pt/GNS was lower than that of Pt/C. The higher CO tolerance of Pt/N-GNP than that of Pt/GNS was ascribed to the presence of a defect in graphene, generated by N-doping, decreasing CO adsorption energy.

scholarly journals Structural, Electronic, and Magnetic Properties of Mn4N Perovskite: Density Functional Theory Calculations and Monte Carlo Study

2019 ◽  
Vol 33 (5) ◽  
pp. 1507-1512 ◽  
Author(s):  
A. Azouaoui ◽  
M. El Haoua ◽  
S. Salmi ◽  
A. El Grini ◽  
N. Benzakour ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Monte Carlo ◽  
Magnetic Properties ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Generalized Gradient ◽  
Critical Temperatures ◽  
Metallic Behavior ◽  
Functional Theory ◽  
Electronic And Magnetic Properties

AbstractIn this paper, we have studied the structural, electronic, and magnetic properties of the cubic perovskite system Mn4N using the first principles calculations based on density functional theory (DFT) with the generalized gradient approximation (GGA). The obtained data from DFT calculations are used as input data in Monte Carlo simulation with a mixed spin-5/2 and 1 Ising model to calculate the magnetic properties of this compound, such as the total, partial thermal magnetization, and the critical temperatures (TC). The obtained results show that Mn4N has a ferrimagnetic structure with two different sites of Mn in the lattice and presents a metallic behavior. The obtained TC is in good agreement with experimental results.

Sign in / Sign up

Export Citation Format

Share Document