相关论文: High-energy-density and superhard nitrogen-rich B-…
The immense interest in carbon nanomaterials continues to stimulate intense research activities aimed to realize carbon nanowires, since linear chains of carbon atoms are expected to display novel and technologically relevant optical,…
Nitriding introduces nitrides into the surface of steels, significantly enhancing the surface me-chanical properties. By combining the variable composition evolutionary algorithm and first-principles calculations based on density functional…
A new extended solid nitrogen, referred to post-layered-polymeric nitrogen (PLP-N), was observed by further heating the layered-polymeric nitrogen (LP-N) to above 2300 K at 161 GPa. The new phase is found to be very transparent and exhibits…
Manganese nitrides should be with amazing properties and promised application, because manganese atom is particular for its magnetism, valence states, high electron density, etc., and N atoms in compounds form different substructures. It is…
We use in-situ high pressure angle dispersive x-ray diffraction measurements to determine the equation of state of cubic tin nitride Sn3N4 under pressure up to about 26 GPa. While we find no evidence for any structural phase transition, our…
In the present work we have proposed the method that allows one to easily estimate hardness and bulk modulus of known or hypothetical solid phases from the data on Gibbs energy of atomization of the elements and corresponding covalent…
We model monolayer graphene-like materials with BC$_6$N stoichiometry where the bonding between the B and the N atoms plays an important role for their physical and chemical properties. Two types of BC$_6$N are found based on the BN bonds:…
How to stabilize nitrogen-rich high-energy-density molecules under conventional conditions is particularly important for the energy storage and conversion of such systems and has attracted extensive attention. In this work, our theoretical…
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…
Structural evolution of a prospective hydrogen storage material, ammonia borane NH3BH3, has been studied at high pressures up to 12 GPa and at low temperatures by synchrotron powder diffraction. At 293 K and above 1.1 GPa a disordered I4mm…
By electron and X-ray diffraction we establish that the CrB$_4$ compound discovered over 40 years ago crystallizes in the $oP10$ (\emph{Pnnm}) structure, in disagreement with previous experiments but in agreement with a recent…
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…
Using ab initio evolutionary simulations, we predict the existence of five novel stable Li-N compounds at pressures from 0 to 100 GPa (Li13N, Li5N, Li3N2, LiN2, and LiN5). Structures of these compounds contain of isolated N ions, N2 dimers,…
We report the discovery of a new class of molecular phases of solid nitrogen at high pressures and temperatures by Raman and infrared spectroscopy and powder x-ray diffraction. Unlike the molecular phases consisting of disk- and sphere-like…
Polynitrogen molecules represent the ultimate high energy-density materials as they have a huge potential chemical energy originating from their high enthalpy. However, synthesis and storage of such compounds remain a big challenge because…
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…
Nitrogen is the fifth most abundant element in the Universe, yet the gas-phase chemistry of N-bearing species remains poorly understood. Nitrogen hydrides are key molecules of nitrogen chemistry. Their abundance ratios place strong…
Gas hydrates are systems of prime importance. In particular, hydrogen hydrates are potential materials of icy satellites and comets, and may be used for hydrogen storage. We explore the H2O-H2 system at pressures in the range 0-100 GPa with…
Orthorhombic (space group: Pnma) Nb2P5 is a high-pressure phase that is quenchable to ambient pressure, which could viewed as the zigzag infinite P chain-inserted NbP2. We report herein the high-pressure crystal growth of Nb2P5 and the…
The stability of different stoichiometric H$_n$Br ($n$=1-7) compounds under pressure are extensively studied using density functional theory calculations. Five new energetically stable stoichiometries of H$_2$Br, H$_3$Br, H$_4$Br, H$_5$Br,…