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We report on a density functional theory study demonstrating the coexistence of weak ferromagnetism and antiferroelectricity in boron-deficient MgB6. A boron vacancy produces an almost one dimensional extended molecular orbital, which is…

Materials Science · Physics 2012-03-09 Igor Popov , Nadjib Baadji , Stefano Sanvito

It is essential to know the arrangement of the atoms in a material in order to compute and understand its properties. Searching for stable structures of materials using first-principles electronic structure methods, such as density…

Materials Science · Physics 2015-03-17 Chris J. Pickard , R. J. Needs

A computation methodology based on ab initio evolutionary algorithms and the spin-polarized density functional theory was developed to predict two-dimensional (2D) magnetic materials. Its application to a model system borophene reveals an…

Magnetic structure of single crystalline TmB4 has been studied by magnetization, magnetoresistivity and specific heat measurements. A complex phase diagram with different antiferromagnetic (AF) phases was observed below TN1 = 11.7 K.…

Strongly Correlated Electrons · Physics 2007-12-05 S. Gabani , S. Matas , P. Priputen , K. Flachbart , K. Siemensmeyer , E. Wulf , A. Evdokimova , N. Shitsevalova

The magnetic structures of small clusters of Fe, Mn, and Cr supported on a Cu(111) surface have been studied with non-collinear first principles theory. Different geometries such as triangles, pyramids and wires are considered and the…

Magnetic anisotropy is one of the important factors in determining magnetic structures. A type of magnetic anisotropy is closely related to the symmetry of crystals. We theoretically investigate magnetic anisotropy and its related magnetic…

Strongly Correlated Electrons · Physics 2024-05-22 Akane Inda , Satoru Hayami

What does the equilibrium atomic, molecular or spin configuration of a glass phase look like? Is there only one unique equilibrium configuration or are there infinitely many configurations of equal energy? The processes and mechanisms…

Disordered Systems and Neural Networks · Physics 2015-06-17 Per Nordblad

Stars form in highly-magnetised, supersonic turbulent molecular clouds. Many of the tools and models that we use to carry out star formation studies rely upon the assumption of cloud isotropy. However, structures like high-density filaments…

Astrophysics of Galaxies · Physics 2020-01-08 James R. Beattie , Christoph Federrath

The different crystal structures of ferromagnetic Ni$_2$MnGa have been calculated using density functional theory (DFT) with special emphasis on the modulated structures 10M and 14M. These are important for understanding the stability of…

Materials Science · Physics 2007-05-23 A. Zayak , W. A. Adeagbo , P. Entel , V. D. Buchelnikov

We present a semiclassical theory of weak disorder effects in small structures and apply it to the magnetic response of non-interacting electrons confined in integrable geometries. We discuss the various averaging procedures describing…

Condensed Matter · Physics 2016-08-31 K. Richter , D. Ullmo , R. A. Jalabert

Magnetic materials and nanostructures based on carbon offer unique opportunities for future technological applications such as spintronics. This article reviews graphene-derived systems in which magnetic correlations emerge as a result of…

Mesoscale and Nanoscale Physics · Physics 2010-04-13 Oleg V. Yazyev

We discuss theoretically how electrons confined to two dimensions in a delta-doped heterostructure can arrange themselves in a droplet-like spatial distribution due to disorder and screening effects when their density is low. We apply this…

Strongly Correlated Electrons · Physics 2007-05-23 V. Tripathi , M. P. Kennett

Magnetic structures of the noncentrosymmetric magnet Sr$_2$MnSi$_2$O$_7$ were examined through neutron diffraction for powder and single-crystalline samples, as well as magnetometry measurements. All allowed magnetic structures under the…

Strongly Correlated Electrons · Physics 2024-10-08 Y. Nambu , M. Kawamata , X. Pang , H. Murakawa , M. Avdeev , H. Kimura , H. Masuda , N. Hanasaki , Y. Onose

Multiscale simulation is a key research tool for the quest for new permanent magnets. Starting with first principles methods, a sequence of simulation methods can be applied to calculate the maximum possible coercive field and expected…

Recent experiments indicate room-temperature ferromagnetism in graphite like materials. This paper offers an multiple spin state analysis to find out the origine of ferromagnetism in case of nano meter size graphene molecule.First principle…

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

We study the electronic and magnetic structure of carbon and nitrogen impurities and interstitials in rutile TiO${_2}$. To this end we perform \textit{ab-initio} calculations of a 48-atom supercell employing the VASP code. In order to…

Materials Science · Physics 2015-01-22 Jacqueline Atanelov , Christoph Gruber , Peter Mohn

Using magnetization measurements, we show that point defects in graphene - fluorine adatoms and irradiation defects (vacancies) - carry magnetic moments with spin 1/2. Both types of defects lead to notable paramagnetism but no magnetic…

Mesoscale and Nanoscale Physics · Physics 2012-05-23 R. R. Nair , M. Sepioni , I-Ling Tsai , O. Lehtinen , J. Keinonen , A. V. Krasheninnikov , T. Thomson , A. K. Geim , I. V. Grigorieva

The ruthenium content of half-metallic Mn$_2$Ru$_x$Ga thin films, with a biaxially-strained inverse Heusler structure, controls the ferrimagnetism that determines their magnetic and electronic properties. An extensive study of…

In this work, polycrystalline NiCrGa half Heusler alloy, which is predicted to be half-metallic ferromagnet from first principles calculations, has been synthesized by arc meting technique and its structural, magnetic as well as the…

Materials Science · Physics 2018-12-26 Madhusmita Baral , M. K. Chattopadhyay , Aparna Chakrabarti , Tapas Ganguli

The configuration and evolution of the magnetic field in star-forming cores are investigated in order to directly compare simulations and observations. We prepare four different initial clouds having different magnetic field strengths and…

Solar and Stellar Astrophysics · Physics 2015-06-11 Akimasa Kataoka , Masahiro N. Machida , Kohji Tomisaka
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