J. H. Abir | Searcharxiv

arXiv2026

Nitrogen based electride superconductor Nb5Ir3N under pressure: multifunctional physical properties from DFT based first-principles investigation

Discovery and study of superconducting electrides have opened new avenues in condensed matter physics, driven by their intriguing multifunctional features spanning ambient and high-pressure regimes. This work investigates the ternary nitride superconductor Nb5Ir3N under pressure ranging from 0 to 20 GPa via density functional theory based simulations. Estimated structural parameters agree well with the available data, confirming their reliability and supporting the validity of this analysis. Negative formation enthalpy, together with evaluated elastic constants and phonon spectra, confirm the structural, thermodynamic, mechanical, and dynamical stability of Nb5Ir3N over the entire pressure range. Pressure dependent elastic constants and polycrystalline elastic moduli are investigated. The compound is categorized as ductile in light of estimated mechanical indices. Elastic anisotropy factors indicate that Nb5Ir3N remains anisotropic, with the degree of anisotropy gradually decreasing as pressure increases. Electronic band structure and density of states are calculated with and without spin orbit coupling to investigate its influence on the electronic structure. Calculated optical response reveals substantial intraband contributions in the low energy region, intense ultraviolet absorption, and strong reflectivity. The spectra exhibit optical anisotropy and a broadening at higher pressures. Pressure induced superconducting features are also discussed qualitatively.

cond-mat.mtrl-sci↗

arXiv2026

Exploring the Physical Properties, Hydrogen Storage Capacity and Thermal Barrier Performance of LaMg2H7: A First-Principles Investigation

LaMg2H7 is a ternary wide band gap semiconductor that is a member of the hydride family. The bulk physical characteristics of the LaMg2H7 compound, including its structural, electronic band structure, elastic, thermal, and optical characteristics, have been examined in this work utilizing density functional theory (DFT). The elastic constants indicate that {\rm LaMg}_2H_7 is mechanically stable, brittle in nature, and anisotropic. This studied compound possesses a moderate level of hardness. The band structure and density of states have been examined to have a better understanding of its electronic behavior. The intrinsic carrier concentrations and effective masses have been determined using the band structure. The gravimetric hydrogen storage capacity (Cwt%) has been calculated, indicating that this compound is suitable for hydrogen storage applications. This compound is dynamically stable, as confirmed by its phonon dispersion. Here, the details of this wide-band-gap semiconductor's reflectivity, absorption coefficient, refractive index, dielectric function, optical conductivity, and loss function are investigated. The substance is a moderate reflector of ultraviolet (UV) light. The absorption and conductivity support the gap in the band structure. The thermodynamic properties, such as bulk modulus, internal energy, specific heat capacity, entropy, thermal expansion coefficient, and Debye temperature, have been explored at varying temperatures and pressures. {\rm LaMg}_2H_7 has a moderate level of melting temperature with higher lattice thermal conductivity. The value of the thermal expansion coefficient and minimum thermal conductivity is highly recommended for use as a thermal barrier coating (TBC).

cond-mat.mtrl-sci↗