This study investigates the structural, electronic, and optical properties of FeAs(1-x)La(x) alloys (x = 0, 0.25, 0.5, 0.75, 1) using the FP-LAPW method within the framework of density functional theory (DFT). The lattice parameter, bulk modulus, and its derivative were determined through Murnaghan’s equation of state, revealing deviations from Vegard's law with increasing lanthanum concentration. Analysis of the electronic band structure and refractive indices highlights changes in the band gap, while energy-volume relationships indicate stability in the Zinc-Blende structure. Further exploration of the orthorhombic phase is suggested to confirm the structural properties. Doping FeAs with rare-earth elements introduces significant challenges due to disparities in ionic size, charge, and chemical behavior, yet it can profoundly impact structural, electronic, and superconducting properties such as charge carrier density and lattice parameters. The results emphasize the importance of precise control over doping concentrations and preparation techniques to achieve stable compounds. This theoretical work underscores the potential of FeAs-based materials for advanced applications, paving the way for further experimental validation.
This paper analyzes the structural, electronic, elastic, thermodynamic, optical and thermoelectric properties of Heusler quaternary compounds CoRuXSb (X: Ti, Zr) using first-principles calculations with the ab initio linearized augmented plane waves at full potential (FP-LAPW) method via the Wien2k code, using density functional theory (DFT) with the TB-mBJ-[Formula: see text] approximation. These compounds are found to be more stable in the ferromagnetic phase with a type-1 structure and adopt semiconducting behavior in both spin states. The TB-mBJ approximation, which is close to the experimental results, reveals that CoRuTiSb and CoRuZrSb have indirect band gaps in both spin channels, but CoRuTiSb has a direct band gap in the down-spin channel. Thus, these compounds are classified as semiconducting in both spin states. Negative formation energies ([Formula: see text]) and positive cohesion energies ([Formula: see text]) indicate thermodynamic stability resulting in strong atomic bonds. Similarly, their dynamic stability is proven by the positive phonon frequencies. Mechanical stability criteria confirm their robustness, while the [Formula: see text] ratio according to the PUGH testifies to their ductility. Thermodynamic analysis shows good thermal properties. Their thermoelectric performances are promising, especially in the spin-down state over the entire temperature range, offering potential applications in applications such as thermocouples and electricity generation from waste heat. Finally, their optical properties suggest possible uses as UV light emitters for high-power light-emitting diodes (LEDs) and as UV filters for protection against harmful UV radiation.
The activities of the Arabic language include various skills that enable learners to acquire mastery of the language. It is impossible to command the Arabic language without mastering its fundamental skills, namely listening, speaking, reading, and writing. This has been emphasized in the teaching process across all pedagogical approaches used in language education curricula. However, each approach often focused on a specific skill, which may have contributed to weaknesses in previous methods. The competency-based approach aimed to address this issue by emphasizing the integrated teaching of all skills. These skills are complementary, as the learner listens, then speaks, then reads, and finally writes. The teaching process under the competency-based approach has worked to achieve this integration to enhance language learning.
The aim of this work is to investigate the existence and multiplicity of solutions to a nonhomogenious quasi-linear second order evolution equation involving a fractional dissipation term of Caputo type in abstract framework. Some Criteria on the existence of at least one or two solutions are obtained by using some well known fixed point theorems for the sum of two operators. An example is presented to validate our analysis.
