Investigation of N C and B C bilayers as anode materials for Li-ion batteries by first-principles calculations.

The best choice today for a realistic method of increasing the energy density of a metal-ion battery is to find novel, effective electrode materials. In this paper, we present a theoretical investigation of the properties of hitherto unreported two-dimensional B C and N C bilayer systems as potential anode materials for lithium-ion batteries. The simulation results show that N C bilayer is not suitable for anode material due to its thermal instability.

The Abraham-Lorentz force and the time evolution of a chaotic system: The case of charged classical and quantum Duffing oscillators.

This paper proves that the Abraham-Lorentz (AL) force can noticeably modify the trajectories of the charged Duffing oscillators over time. The influence of the reaction force on the oscillator evolution is strongly enhanced if the system is considered at the level of quantum mechanics. For example, the AL force examined within the scope of Newtonian description can change the trajectory of the Duffing oscillator only if it has the mass of an electron.

Two-dimensional B[Formula: see text]C as a potential anode material for Mg-ion batteries with extremely high theoretical capacity.

The development of new high-capacity anode materials using ions other than lithium as a charge carrier is one of the essential strategies in searching for next-generation high-performance rechargeable batteries. Herein, using first-principles computations, we explore a B[Formula: see text]C monolayer as a potential anode material for Mg-ion batteries. The high stability of the free-standing B[Formula: see text]C monolayer has been demonstrated via calculating the adsorption energy, phonon dispersion, and ab-initio molecular dynamics simulations.

New superconducting superhydride LaCH at relatively low stabilization pressure.

Motivated by the recent experimental discovery of high-temperature carbonaceous sulfur hydride (C-S-H), we have systematically explored the superconductivity of a carbonaceous lanthanum hydride (C-La-H) ternary compound in the pressure range of 50-250 GPa. Based on first-principles calculations and strong-coupling Migdal-Eliashberg theory, we find that a hitherto unreported LaCH ternary system is dynamically and thermally stable above 70 GPa in a clathrate structure with space group 3̄ and exhibits a superconducting critical temperature, , in the range of 69-140 K.

The influence of heteroatom doping on local properties of phosphorene monolayer.

New energy storage technologies that can serve as a reliable alternative to lithium-ion batteries are in the spotlight. Particular attention has been recently devoted to magnesium-ion systems due to the considerable abundance of this element and also due to its promising electro-chemical performance. Our results show that monolayer black phosphorene doped by B, Sc, Co, and Cu atoms possesses good structural stability with the minimal cohesive energy of [Formula: see text] eV/atom, the adsorption energy per Mg atom ranging from [Formula: see text] to [Formula: see text] eV, and the charge transfer from double-side adsorbed single Mg-ions to the B-substituted phosphorene increased by [Formula: see text]0.

Stability and superconductivity of Ca-intercalated bilayer blue phosphorene.

Superconductivity attracts much attention in two-dimensional (2D) compounds due to their potential application in nano-superconducting devices. Inspired by a recent experiment reporting the superconducting state in twisted bilayer graphene, here, based on the first-principles density-functional theory complemented by the Eliashberg formalism, we have verified the stability and predicted superconductivity in Ca-intercalated bilayer blue phosphorene. The electron and phonon properties and electron-phonon coupling show that AA- and AA'-stacking orders of the phosphorene bilayer are dynamically stable and exhibit conventional phonon-mediated superconductivity with superconducting transition temperatures (Tc) of 11.

Nonadiabatic superconductivity in a Li-intercalated hexagonal boron nitride bilayer.

When considering a Li-intercalated hexagonal boron nitride bilayer (Li-hBN), the vertex corrections of electron-phonon interaction cannot be omitted. This is evidenced by the very high value of the ratio λω/ε ≈ 0.46, where λ is the electron-phonon coupling constant, ω is the Debye frequency, and ε represents the Fermi energy.

Computational Design of Novel Hydrogen-Rich YS-H Compounds.

The recent successful findings of HS and LaH compressed above 150 GPa with a record high (above 200 K) have shifted the focus on hydrogen-rich materials for high superconductivity at high pressure. Moreover, some studies also report that transition-metal ternary hydrides could be synthesized at a relatively low pressure (∼10 GPa). Therefore, it is highly desirable to investigate the crystal structures of ternary hydrides compounds at high pressure since they have been long considered as promising superconductors and hydrogen-storage materials with a high , and can be possibly synthesized at low pressure as well.

Superconductivity in bilayer graphene intercalated with alkali and alkaline earth metals.

With the enormous research activity focused on graphene in recent years, it is not surprising that graphene superconductivity has become an attractive area of research. To date, no superconducting properties have been experimentally observed in the pristine form of graphene but controllable structure manipulation is a promising way to induce a superconducting state in graphene-based systems. Therefore, herein we investigate the possible superconductivity in two-layer graphene intercalated with atoms of alkali and alkaline earth metals.

Structural, electronic, vibrational, and superconducting properties of hydrogenated chlorine.

Recent measurements have set a new record for the superconducting transition temperature ( ) at which a material losses electrical resistivity and exhibits ideal diamagnetism. Theory-oriented experiments show that the compressed hydride of Group VI (hydrogen sulfide, HS) exhibits a superconducting state at 203 K. Moreover, a Group V hydride (phosphorus hydride, PH) has also been studied and its reached a maximum of 103 K.

Unusual sulfur isotope effect and extremely high critical temperature in HS superconductor.

Recent experiments have set a new record for the transition temperature at which a material (hydrogen sulfide, HS) becomes superconducting. Moreover, a pronounced isotope shift of T in DS is evidence of an existence of phonon-mediated pairing mechanism of superconductivity that is consistent with the well established Bardeen-Cooper-Schrieffer scenario. Herein, we reported a theoretical studies of the influence of the substitution of S atoms by the heavier isotopes S, S and S on the electronic properties, lattice dynamics and superconducting critical temperature of HS.

First-principles study of superconducting hydrogen sulfide at pressure up to 500 GPa.

We investigate the possibility of achieving the room-temperature superconductivity in hydrogen sulfide (HS) through increasing external pressure, a path previously widely used to reach metallization and superconducting state in novel hydrogen-rich materials. The electronic properties and superconductivity of HS in the pressure range of 250-500 GPa are determined by the first-principles calculations. The metallic character of a body-centered cubic Im[Formula: see text]m structure is found over the whole studied pressure.

Quantitative analysis of nonadiabatic effects in dense HS and PH superconductors.

The comparison study of high pressure superconducting state of recently synthesized HS and PH compounds are conducted within the framework of the strong-coupling theory. By generalization of the standard Eliashberg equations to include the lowest-order vertex correction, we have investigated the influence of the nonadiabatic effects on the Coulomb pseudopotential, electron effective mass, energy gap function and on the 2Δ(0)/T ratio. We found that, for a fixed value of critical temperature (178 K for HS and 81 K for PH), the nonadiabatic corrections reduce the Coulomb pseudopotential for HS from 0.