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Related papers: Void defect induced magnetism and structure change…

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Void defect is a possible origin of ferromagnetic like feature of pure carbon material. Applying density functional theory to void defect induced graphene nano ribbon (GNR), a detailed relationship between multiple spin state and structure…

Materials Science · Physics 2021-07-06 Norio Ota , Laszlo Nemes

Void-defect induced magnetism of graphene molecule was recently reported in our previous paper of this series study. This paper investigated the case of hydrogenated graphene molecule, in chemical term, polycyclic aromatic hydrocarbon…

Astrophysics of Galaxies · Physics 2021-07-06 Norio Ota , Aigen Li , Laszlo Nemes

It is well known since 2010 that fullerene C60 is widespread through the interstellar space. Also, it is well known that graphene is a source material for synthesizing fullerene. Here, we simply assume the occurrence of graphene in space.…

Astrophysics of Galaxies · Physics 2020-08-03 Norio Ota , Aigen Li , Laszlo Nemes , Masaaki Otsuka

Understanding the magnetic properties of graphenic nanostructures is instrumental in future spintronics applications. These magnetic properties are known to depend crucially on the presence of defects. Here we review our recent theoretical…

Mesoscale and Nanoscale Physics · Physics 2013-04-02 Elton J. G. Santos , Andres Ayuela , Daniel Sanchez-Portal

It had been understood that astronomically observed infrared spectrum of carbon rich planetary nebula as like Tc 1 and Lin 49 comes from fullerene (C60). Also, it is well known that graphene is a raw material for synthesizing fullerene.…

Astrophysics of Galaxies · Physics 2019-04-24 Norio Ota

Room temperature ferromagnetic materials composed only by light elements like carbon, hydrogen and/or nitrogen, so called carbon magnet, are very attractive for creating new material categories both in science and industry. Recently several…

Mesoscale and Nanoscale Physics · Physics 2011-01-24 Norio Ota , Narjes Gorjizadeh , Yoshiyuki Kawazoe

Theoretical calculations, based on hybrid exchange density functional theory, are used to show that in graphene a periodic array of defects generates a ferromagnetic ground state at room temperature for unexpectedly large defect…

Materials Science · Physics 2009-11-13 L. Pisani , B. Montanari , N. M. Harrison

We study from first principles the magnetism in graphene induced by single carbon atom defects. For two types of defects considered in our study, the hydrogen chemisorption defect and the vacancy defect, the itinerant magnetism due to the…

Materials Science · Physics 2007-05-23 Oleg V. Yazyev , Lothar Helm

Graphene is a model system for the study of electrons confined to a strictly two-dimensional layer1 and a large number of electronic phenomena have been demonstrated in graphene, from the fractional2, 3 quantum Hall effect to…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 Jian-Hao Chen , W. G. Cullen , E. D. Williams , M. S. Fuhrer

Several experiments have recently found room-temperature ferromagnetism in graphite-like carbon based materials. This paper offers a model explaining such ferromagnetism by using an asymmetric nano-graphene. Our first typical model is…

Mesoscale and Nanoscale Physics · Physics 2011-01-28 Norio Ota , Narjes Gorjizadeh , Yoshiyuki Kawazoe

We have carried out ab initio electronic structure calculations on graphane (hydrogenated graphene) with single and double vacancy defects. Our analysis of the density of states reveal that such vacancies induce the mid gap states and…

Materials Science · Physics 2010-02-11 Bhalchandra S. Pujari , D. G. Kanhere

The pristine graphene is strongly diamagnetic. However, graphene with single carbon atom defects could exhibit paramagnetism with local magnetic moments ~ 1.5 per vacancy1-6. Theoretically, both the electrons and electrons of graphene…

Materials Science · Physics 2017-02-13 Yu Zhang , Si-Yu Li , Wen-Tian Li , Jia-Bin Qiao , Wen-Xiao Wang , Long-Jin Yin , Lin He

Magnetism of fullerene C60 was studied by three methods of the density functional theory (DFT) calculation, laboratory experiment and astronomical observation. DFT revealed that the most stable spin state was non-magnetic one of Sz=0/2.…

Astrophysics of Galaxies · Physics 2021-11-02 Norio Ota , Aigen Li , Laszlo Nemes , Masaaki Otsuka

Atomic vacancies have a strong impact in the mechanical, electronic and magnetic properties of graphene-like materials. By artificially generating isolated vacancies on a graphite surface and measuring their local density of states on the…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 M. M. Ugeda , I. Brihuega , F. Guinea , J. M. Gomez-Rodriguez

We provide a thorough study of a carbon divacancy, a fundamental but almost unexplored point defect in graphene. Low temperature scanning tunneling microscopy (STM) imaging of irradiated graphene on different substrates enabled us to…

The magnetic properties of disordered graphene and irradiated graphite are systematically studied using a combination of mean-field Hubbard model and first-principles calculations. By considering large-scale disordered models of graphene, I…

Materials Science · Physics 2008-07-17 Oleg V. Yazyev

In order to study a magnetic principle of carbon based materials, multiple spin state of zigzag edge modified graphene molecules are analyzed by the first principle density functional theory to select suitable modification element. Radical…

Mesoscale and Nanoscale Physics · Physics 2011-06-15 Norio Ota , Narjes Gorjizadeh , Yoshiyuki Kawazoe

The detailed analysis of the problem of possible magnetic behavior of the carbon-based structures was fulfilled to elucidate and resolve (at least partially) some unclear issues. It was the purpose of the present paper to look somewhat more…

Strongly Correlated Electrons · Physics 2013-03-26 A. L. Kuzemsky

We address the electronic structure and magnetic properties of vacancies and voids both in graphene and graphene ribbons. Using a mean field Hubbard model, we study the appearance of magnetic textures associated to removing a single atom…

Mesoscale and Nanoscale Physics · Physics 2008-11-27 J. J. Palacios , J. Fernandez-Rossier , L. Brey

The presence of defects such as vacancies in solids has prominent effects on their mechanical properties. It not only modifies the stiffness and strength of materials, but also changes their morphologies. The latter effect is extremely…

Mesoscale and Nanoscale Physics · Physics 2015-08-13 Zhigong Song , Zhiping Xu
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