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Related papers: Ionic high-pressure form of elemental boron

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Being the simplest element with just one electron and proton the electronic structure of the Hydrogen atom is known exactly. However, this does not hold for the complex interplay between them in a solid and in particular not at high…

Materials Science · Physics 2014-06-23 Sam Azadi , Thomas D. Kühne

We have performed a combined experimental and theoretical study of ethane and methane at high pressures up to 120 GPa at 300 K using x-ray diffraction and Raman spectroscopy and the USPEX ab-initio evolutionary structural search algorithm,…

Wurtzite Boron Nitride ($w$BN) is a wide band gap BN polymorph with peculiar mechanical properties (hardness and stiffness). After its first synthesis in 1963 as a transformation of hexagonal BN ($h$BN) under high temperature and pressure…

Materials Science · Physics 2023-05-31 Martino Silvetti , Claudio Attaccalite , Elena Cannuccia

Elementary semiconductors are rare and attractive, especially for low-dimensional materials. Unfortunately, most of boron nanostructures were found to be metallic, despite of their typical semiconducting bulk structure. Herein, we propose a…

Mesoscale and Nanoscale Physics · Physics 2018-11-01 Shao-Gang Xu , Xiao-Tian Li , Yu-Jun Zhao , Wang-Ping Xu , Ji-Hai Liao , Xiu-Wen Zhang , Hu Xu , Xiao-Bao Yang

Two novel of boron-rich selenides, orthorhombic B$_6$Se and rhombohedral B$_{12}$Se, have been recently synthesized at high pressure - high temperature conditions. Room-temperature compressibilities of these phases were studied in a diamond…

Materials Science · Physics 2021-09-15 Kirill A. Cherednichenko , Yann Le Godec , Vladimir L. Solozhenko

The atomic structure of icosahedral B$_4$C boron carbide is determined by comparing existing infra-red absorption and Raman diffusion measurements with the predictions of accurate {\it ab initio} lattice-dynamical calculations performed for…

Materials Science · Physics 2009-10-31 R. Lazzari , N. Vast , J. M. Besson , S. Baroni , A. Dal Corso

On account of the rapid development of noble gas chemistry in the past half-century both xenon and krypton compounds can now be isolated in macroscopic quantities. The same though does not hold true for the next lighter group 18 element,…

Materials Science · Physics 2021-11-01 Dominik Kurzydłowski , Patryk Zaleski-Ejgierd

A model of the interstitial diffusion of ion-implanted boron during rapid thermal annealing of silicon layers previously amorphized by implantation of germanium has been proposed. It is supposed that the boron interstitials are generated…

Materials Science · Physics 2009-05-01 O. I. Velichko , N. V. Kniazhava

The assessed phase diagram of the boron-carbon system contains a single non-stoichiometric boron-carbide phase of rhombohedral symmetry with a broad, thermodynamically improbable, low temperature composition range. We combine first…

Materials Science · Physics 2014-02-10 William P. Huhn , Michael Widom

More than 20 crystalline and amorphous phases have been reported for ice so far. This extraordinary polymorphism of ice arises from the geometric flexibility of hydrogen bonds and hydrogen ordering, and makes ice a unique presence with its…

Noting the structural relationships between phases of carbon and boron carbide with phases of boron nitride and boron subnitride, we investigate their mutual solubilities using a combination of first principles total energies supplemented…

Materials Science · Physics 2016-04-13 Hantao Zhang , Sanxi Yao , Michael Widom

Helium is generally understood to be chemically inert and this is due to its extremely stable closed-shell electronic configuration, zero electron affinity and an unsurpassed ionization potential. It is not known to form thermodynamically…

Group I/II materials exhibit unexpected structural phase transitions at high pressures, providing potential insight into the origins of elemental superconductivity. We present here a computational study of elemental barium and binary…

Materials Science · Physics 2012-07-16 Joshua A. Taillon , William W. Tipton , Richard G. Hennig

Important properties of complex quantum many-body systems and their phase diagrams can often already be inferred from the impurity limit. The Bose polaron problem describing an impurity atom immersed in a Bose-Einstein condensate is a…

Quantum Gases · Physics 2024-03-06 Arthur Christianen , J. Ignacio Cirac , Richard Schmidt

Due to a large discrepancy between theory and experiment, the electronic character of crystalline boron carbide B$_{13}$C$_{2}$ has been a controversial topic in the field of icosahedral boron-rich solids. We demonstrate that this…

Materials Science · Physics 2015-09-01 A. Ektarawong , S. I. Simak , L. Hultman , J. Birch , B. Alling

The simple alkali metal Na, that crystallizes in a body-centred cubic structure at ambient pressure, exhibits a wealth of complex phases at extreme conditions as found by experimental studies. The analysis of the mechanism of stabilization…

Materials Science · Physics 2009-09-25 V F Degtyareva , O Degtyareva

The structural, electronic, and spectroscopic properties of a high-pressure phase of methane hydrate (MH-III) are studied by first principles electronic structure calculations. A detailed analysis of the atomic positions suggests that {\it…

Materials Science · Physics 2007-05-23 Toshiaki Iitaka , Toshikazu Ebisuzaki

It is generally difficult to quantify the amounts of light elements in materials because of their low X-ray-scattering power, as this means that they cannot be easily estimated via X-ray analyses. Meanwhile, the recently reported layered…

In this work we explore the phase diagram of the binary Nb-S system from ambient pressures up to 250 GPa using $ab$ $initio$ evolutionary crystal structure prediction. We find several new stable compositions and phases, especially in the…

Materials Science · Physics 2021-01-13 Roman Lucrezi , Christoph Heil

Two-dimensional (2D) structures of boron atoms so called borophene, have recently attracted remarkable attention. In a latest exciting experimental study, a hydrogenated borophene structure was realized. Motivated by this success, we…