Related papers: Ionic high-pressure form of elemental boron
The recent discovery of pure boron nanotubes raises questions about their detailed atomic structure. Previous simulations predicted tubular structures with smooth or puckered surfaces. Here, we present some novel results based on ab initio…
Boron carbide, a lightweight, high temperature material, has various applications as a structural material and as a neutron absorber. The large solubility range of carbon in boron, between $\approx$ 9% and 20%, stems from the…
The structures, stability, mechanical and electronic properties of a-boron and its twined brother a*-boron have been studied by first-principles calculations. Both a-boron and a*-boron consist of equivalent icosahedra B12 clusters in…
Boron carbide exhibits intrinsic substitutional disorder over a broad composition range. The structure consists of 12-atom icosahedra placed at the vertices of a rhombohedral lattice, together with a 3-atom chain along the 3-fold axis. In…
Boron suboxide B6O, the hardest known oxide, has an R-3m crystal structure ({\alpha}-B6O) that can be described as an oxygen-intercalated structure of {\alpha}-boron, or, equivalently, as a cubic close packing of B12 icosahedra with two…
In the search for MgB2-like phonon-mediated superconductors we have carried out a systematic density functional theory study of the Ca-B system, isoelectronic to Mg-B, at ambient and gigapascal pressures. A remarkable variety of candidate…
An ideal material for on-board hydrogen storage must release hydrogen at practical temperature and pressure and also regenerate efficiently under similarly gentle conditions. Therefore, thermodynamically, the hydride material must lie…
The phase relations in boron have been investigated at high pressure and high temperature using a multianvil apparatus, and the quenched sample has been analyzed by x-ray diffraction, Raman spectra and transmission electron microscopy. We…
We identify a new family of boron-rich compounds consisting of interconnected B$_{12}$ icosahedra, and electropositive guest atoms ($X$) in interstitial sites. These structures were found through first-principles crystal structure…
Two-dimensional systems have strengthened their position as one of the key materials for novel applications. Very recently, boron joined the distinguished group of elements that are confirmed to possess 2D allotropes, named borophenes. In…
The formation of boron carbide under high pressures and from elemental reactants has been studied and optimum parameters have been determined by varying the (P, T, reactants) conditions. To this end, stoichiometric mixtures of commercial…
Boron carbide is a ceramic material with unique properties widely used in numerous, including armor, applications. Its mechanical properties, mechanism of compression, and limits of stability are of both scientific and practical value.…
Boron Carbide exhibits a broad composition range, implying a degree of intrinsic substitutional disorder. While the observed phase has rhombohedral symmetry (space group R3(bar)m), the enthalpy minimizing structure has lower, monoclinic,…
The crystal structure of iron in the Earth's inner core remains debated. Most recent experiments suggest a hexagonal-close-packed (hcp) phase. In simulations, it has been generally agreed that the hcp-Fe is stable at inner core pressures…
A highly efficient semi-empirical Hamiltonian has been developed and applied to model the compact boron clusters with the intermediate size. The Hamiltonian, in addition to the inclusion of the environment-dependent interactions and…
Structure and electronic properties of two unusual boron clusters obtained by fusion of borozene rings has been studied by means of first principles calculations, based on the generalized-gradient approximation of the density functional…
At high pressure, the typical behavior of elements dictated by the periodic table - including oxidation numbers, stoichiometries in compounds, and reactivity, to name but a few - is altered dramatically. As pressure is applied, the…
Boron nitride (BN) is a structurally versatile insulator since it can be found in several crystalline structures with interesting mechanical and electrical properties, making this material attractive for technological applications. Seeking…
The crystallographic structure of iron under extreme conditions is a key benchmark for cutting-edge experimental and numerical methods. Moreover, it plays a crucial role in understanding planetary cores, as it significantly influences the…
Quasi-hydrostatic compression of rhombohedral boron monosulfide (r-BS) has been studied up to 50 GPa at room temperature using diamond-anvil cells and angle-dispersive synchrotron X-ray diffraction. A fit of the experimental P-V data to the…