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This study provides a thorough analysis of magnesium oxynitride (MgON), employing first-principles calculations to investigate its potential for electronic, thermoelectric, and optical applications. The main objective was to comprehend the fundamental electronic, thermoelectric, and optical parameters of MgON using density functional theory (DFT) calculations. In electronic properties, the density of states (DOS) spectra revealed the significant contribution of Mg-s and O-p states for pristine MgO, while N-p states provide the maximum contributions with overlapping at the Fermi level in nitrogen-containing compositions. The band structure depicted a direct nature for undoped and doped MgO, and the bandgap of compositions was observed to decrease with the increment in nitrogen concentration. The thermoelectric properties of pure and N-doped MgO compositions were evaluated, which showed significant variations with an increase in temperature and doping. Furthermore, the optical properties of MgON were inspected and found to enhance optical conductivity, and absorption coefficient, whereas the refractive index and dielectric constant decrease at specific energy regions for elevated dopant content, which suggests its suitability for optoelectronic applications. Overall, this study reveals the versatility of MgON, making it a potential candidate for advanced electronic, thermoelectric, and optical applications.

We propose a microscopic approach for a description of interaction of the ideal gas of alkali atoms with a weak electromagnetic radiation. The description is constructed in the framework of the Green functions formalism that is based on a new formulation of the second quantization method in case of the bound states (atoms) presence. For a gas in the Bose-condensed (BEC) state we study the dependencies of the propagation velocity and damping rate on the microscopic characteristics of the system. For a condensed dilute gas of sodium atoms we find the conditions of the group velocity reducing for optical pulses tuned up close to the resonant transitions. We also show that the slowing phenomenon can strongly depend on the intensity of the external static magnetic field.

In this work, we have extensively investigated the characteristics of ternary half-Heusler (HH) materials, specifically NaAlX (X$=$C, Si and Ge), employing ab-initio computations in density functional theory (DFT) framework. Various aspects, including stability parameters, electronic, optical and thermoelectric (TE) parameters have been examined. The computed lattice constants of NaAlX (X$=$C, Si and Ge) were found to be, respectively, 5.398, 6.301 and 6.389Å which are in excellent agreement with the previously available data. The electronic band structures showed that the studied materials exhibit semiconducting behavior with a corresponding band gap of 1.961, 0.999 and 0.846eV, respectively. Specifically, NaAlC and NaAlGe compounds were found to have a direct energy band gap at the $\mathrm{\Gamma }$-point, while NaAlSi displayed an indirect band gap at the $\mathrm{\Gamma }$–X point. Elastic and thermodynamic parameters were examined, confirming that the titled compounds possess mechanical, dynamic and thermal stability. Additionally, the optical response of the materials has been analyzed within an energy range of 0–13eV. The TE parameters exhibited maximum ZT values of 0.998, 0.992 and 0.990 for NaAlX (X$=$C, Si and Ge) materials, respectively, at 300K, suggesting promising TE performance at room temperature.

We propose a microscopic approach for a description of interaction of the ideal gas of alkali atoms with a weak electromagnetic radiation. The description is constructed in the framework of the Green functions formalism that is based on a new formulation of the second quantization method in case of the bound states (atoms) presence. For a gas in the Bose-condensed (BEC) state we study the dependencies of the propagation velocity and damping rate on the microscopic characteristics of the system. For a condensed dilute gas of sodium atoms we find the conditions of the group velocity reducing for optical pulses tuned up close to the resonant transitions. We also show that the slowing phenomenon can strongly depend on the intensity of the external static magnetic field.