相关论文: Phonon and Elastic Instabilities in MoC and MoN
Although many binary compounds have the B2 (CsCl-type) structure in the thermodynamic phase diagram, an origin of the structural stability is not understood well. Here, we focus on 416 compounds in the B2 structure extracted from the…
I study dynamical instabilities in Ta$_2$NiSe$_5$ using density functional theory based calculations. The calculated phonon dispersions show two unstable optical branches. All the acoustic branches are stable, which shows that an elastic…
The electron-excitation induced bond strength variations in metals have been predicted from density-functional theory calculations and observed experimentally, while the microscopic mechanism has yet to be elucidated. Here, we present a…
Two-dimensional (2D) superconductors attracted growing interest in condensed-matter physics research. In this work, we explore the superconducting properties of surface-functionalized, out-of-plane ordered double transition-metal MXenes…
A metastable phase of NbN with superconducting Tc=16.4 K was reported recently by Treece and collaborators. The reported structure of the thin film sample deviates from the rocksalt (B1) NbN structure with 25% ordered vacancies on each…
Our goals are to assist a non-practitioner understand likely resolution of the controversy about the boson that couples Cooper pairs in Cu oxides and to consider if high temperature superconductivity (HTS) in solid oxides might be related…
By combining neutron inelastic scattering (NIS) and first-principles calculations, we have investigated the lattice dynamics of MOF5. The structural stability of MOF5 was evaluated by calculating the three cubic elastic constants. We find…
Plasticity in body centered cubic (bcc) refractory metals are largely due to the stress tensor induced either by solute or thermal activation. The mechanism of the solute atom(s) residence causes instability in such metals. Earlier research…
We present our study on atomic, electronic, magnetic and phonon properties of one dimensional honeycomb structure of molybdenum disulfide (MoS$_2$) using first-principles plane wave method. Calculated phonon frequencies of bare armchair…
We report a previously unknown monolayer borophene allotrope and we call it super-B with a flat structure based on the ab initio calculations. It has good thermal, dynamical, and mechanical stability compared with many other typical…
We present neutron total scattering and density functional theory studies on quasi-one-dimensional superconducting K$_2$Cr$_3$As$_3$ revealing a frustrated structural instability. Our first principles calculations find a significant phonon…
We investigate the superconductivity of carbon compounds with a sodalite structure, which are similar to hydrogen compounds showing the high-temperature superconductivity. A systematic analysis by first-principles calculations is carried…
In the quest for stable 2D arsenic phases, four different structures have been recently claimed to be stable. We show that, due to phonon contributions, the relative stability of those structures differs from previous reports and depends…
In this paper, we reported the structural properties and superconductivity of Mg(B1-xCx)2 compounds. Powder x-ray diffraction results indicate that the samples crystallize in a hexagonal AlB2-type structure. Due to the chemical activity of…
We present a workflow that iteratively combines \textit{ab-initio} calculations with a machine-learning (ML) guided search for superconducting compounds with both dynamical stability and instability from imaginary phonon modes, the latter…
Sodium chloride (NaCl), or rocksalt, is well characterized at ambient pressure. Due to the large electronegativity difference between Na and Cl atoms, it has highly ionic chemical bonding, with stoichiometry 1:1 dictated by charge balance,…
Lithium transition metal phospho-olivines are useful electrode materials, owing to their stability, high safety, low cost and cyclability. We report phonon studies using neutron inelastic scattering experiments, ab-initio density functional…
Ab initio phonon calculations for the nonpolar reference structures of the (001), (110), and (111) PbZrO_3/PbTiO_3 [1:1] superlattices are presented. The unstable polar modes in the tetragonal (001) and (110) structures are confined in…
We employ the density functional theory to study a structural transition of MnO from B1 (rocksalt) to B8 (NiAs) structures that was observed experimentally at pressures around 100 GPa. We utilize all-electron description as well as…
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…