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Related papers: Structure and magnetism of disordered carbon

200 papers

From density functional theory investigations helped with crystal chemistry rationale, single-atom C, embedded in layered hexagonal CCn with n = 6, 12, 18 networks, is stable in a magnetic state with M(C)= 2 Bohr Magneton (BM). The examined…

Materials Science · Physics 2020-07-28 Samir F Matar

We have developed and implemented a self-consistent density functional method using standard norm-conserving pseudopotentials and a flexible, numerical LCAO basis set, which includes multiple-zeta and polarization orbitals. Exchange and…

Abridged. A large fraction of stars are found in binary systems. It is therefore important for our understanding of the star formation process, to investigate the fragmentation of dense molecular cores. We study the influence of the…

Astrophysics · Physics 2009-11-13 P. Hennebelle , R. Teyssier

Magnetic fields are believed to play an important role in controlling the stability and contraction of dense condensations of gas and dust leading to the formation of stars and planetary systems. In the present study, the magnetic field of…

A scheme to calculate the electronic structure of systems having a spiral magnetic structure is presented. The approach is based on the KKR (Korringa-Kohn-Rostoker) Green's function formalism which allows in combination with CPA (Coherent…

Strongly Correlated Electrons · Physics 2013-08-08 S. Mankovsky , G. H. Fecher , H. Ebert

We use ab initio density functional calculations to study the formation and structural as well as thermal stability of cellular foam-like carbon nanostructures. These systems with a mixed $sp^2/sp^3$ bonding character may be viewed as…

Materials Science · Physics 2015-06-11 Zhen Zhu , David Tománek

HoNiSi$_{3}$ is an intermetallic compound characterized by two successive antiferromagnetic transitions at $T_{N1} = 6.3$ K and $T_{N2} = 10.4$ K. Here, its zero-field microscopic magnetic structure is inferred from resonant x-ray magnetic…

Electronic structure calculations of the Verwey ground state of magnetite, Fe3O4, using density functional theory with treatment of on-site Coulomb interactions (DFT+U scheme) are reported. These calculations use the recently-published…

Strongly Correlated Electrons · Physics 2013-01-16 Mark Senn , Ingo Loa , Jon P. Wright , J. Paul Attfield

A simple discrete model for magnetic structures of chromium nanoclusters, found with the help of local-spin DFT by Kohl and Bertsch, still confirms their conclusion that in most of the clusters the magnetic moments are not collinear;…

Statistical Mechanics · Physics 2007-05-23 Ana Proykova , Dietrich Stauffer

Isolated electrostatic structures are observed throughout much of the 4 Re by 19.6 Re Cluster orbit. These structures are observed in the Wideband plasma wave instrument's waveform data as bipolar and tripolar pulses. These structures are…

Space Physics · Physics 2015-06-26 J. S. Pickett , L. -J. Chen , S. W. Kahler , O. Santolik , D. A. Gurnett , B. T. Tsurutani , A. Balogh

The electronic structure, bonding and magnetism in graphene containing vacancies are studied using density-functional methods. The single-vacancy graphene ground state is spin polarized and structurally flat. The unpolarized state is non…

Mesoscale and Nanoscale Physics · Physics 2008-07-11 M. W. C. Dharma-wardana , Marek Z. Zgierski

We perform Monte Carlo simulations to study the interplay of structural and magnetic order in single layer graphene covered with magnetic adatoms. We propose that the presence of ripples in the graphene structure can lead to clustering of…

Strongly Correlated Electrons · Physics 2009-12-08 T. G. Rappoport , Bruno Uchoa , A. H. Castro Neto

Frustrated magnetism plays a central role in the phenomenology of exotic quantum states. However, because the magnetic structures of frustrated systems are aperiodic, there has always been the problem that they cannot be determined using…

Materials Science · Physics 2013-05-30 Joseph A. M. Paddison , Andrew L. Goodwin

Magnetized plasmas are well known to exhibit a rich spectrum of collective modes. Here, we focus on the density modes in dense or cold plasmas, where strong coupling effects alter the mode spectrum known from traditional weakly coupled…

Plasma Physics · Physics 2023-01-10 Hanno Kählert , Michael Bonitz

Magnetism - the spontaneous alignment of atomic moments in a material - is driven by quantum-mechanical `exchange' interactions which operate over atomic distances as a result of the fundamental symmetry of electrons. Currently, one of the…

We report a first-principles study of the magnetic properties, site disorder and magneto-structural coupling in multiferroic gallium ferrite (GFO) using local spin density approximation (LSDA+U) of density functional theory. The…

Materials Science · Physics 2012-04-16 Amritendu Roy , Rajendra Prasad , Sushil Auluck , Ashish Garg

The investigation of magnetic energy landscapes and the search for ground states of magnetic materials using ab initio methods like density functional theory (DFT) is a challenging task. Complex interactions, such as superexchange and…

Materials Science · Physics 2024-12-24 Jakob Baumsteiger , Lorenzo Celiberti , Patrick Rinke , Milica Todorović , Cesare Franchini

Eulerian and Lagrangian tools are used to detect coherent structures in the velocity and magnetic fields of a mean--field dynamo, produced by direct numerical simulations of the three--dimensional compressible magnetohydrodynamic equations…

Solar and Stellar Astrophysics · Physics 2013-11-21 Erico L. Rempel , Abraham C. -L. Chian , Axel Brandenburg , Pablo R. Muñoz

We investigate the electronic structure of gap and band tail states in amorphous silicon. Starting with two 216-atom models of amorphous silicon with defect concentration close to the experiments, we systematically study the dependence of…

Disordered Systems and Neural Networks · Physics 2009-11-10 Raymond Atta-Fynn , Parthapratim Biswas , Pablo Ordejon , D. A. Drabold

Density functional calculations are used to study magnetic and electronic properties of the spinel ferrites, ZnFe$_2$O$_4$ and MnFe$_2$O$_4$. Correct magnetic orderings are obtained. ZnFe$_2$O$_4$ is predicted to be a small gap insulator in…

Condensed Matter · Physics 2009-11-07 D. J. Singh , M. Gupta , R. Gupta