Ab initio exploration of A2AlAgCl6 (A = Rb, Cs): unveiling potentials for UV optoelectronic applications.

CONTEXT AND RESULTS: In this study, we have explored the electronic and optical properties of A2AlAgCl6 (A = Rb, Cs), revealing their potential applications in UV devices. Our investigation demonstrates that Rb2AlAgCl6 and Cs2AlAgCl6 possess remarkable mechanical and thermodynamic stability, alongside direct band gaps of 4.25 eV and 4.20 eV, respectively. The optical properties, including the dielectric function, absorption coefficient, and reflectivity, underscore the suitability of these materials for UV device applications. This work serves as a foundational reference for future experimental endeavors aiming to leverage these characteristics for practical uses in scientific research. COMPUTATIONAL AND THEORETICAL TECHNIQUES: The study utilizes first-principles calculations based on the Wien2k code, employing GGA-PBE and mBJ exchange-correlation functional to analyze the cubic structure of the space group Fm-3m. Detailed computational analyses were conducted to investigate the band structure, density of states, and optical properties, particularly focusing on Cs2AlAgCl6. This methodological approach not only confirms the materials' impressive stability and optical characteristics but also provides a robust framework for assessing their potential in UV technology applications. Our computational strategy offers insights into the effectiveness of these methodologies for future experimental validation and practical deployment in the research domain.

Investigating the physical and optoelectronic characteristics of Co2ZrZ compounds: findings from computational analysis and thermoelectric evaluation.

CONTEXT AND RESULTS: The study examines the physical characteristics of Co2ZrZ compounds using the Wien2k code and the Anisimov and Gunnarsson approach. Results show metallic attributes in Co2ZrBi and Co2ZrAs, while Co2ZrPb exhibits semi-metallic tendencies. Energy gap evaluations reveal significant infrared transitions, indicating altered electron mobility compensated by increased ultraviolet absorption. These compounds have potential in space solar energy applications due to UV light absorption capabilities, especially in Co2ZrPb. The study also identifies optical phenomena like "super-luminescence" and plasmatic oscillations. COMPUTATIONAL AND THEORETICAL TECHNIQUES: The study uses computational techniques like Wien2k calculation code and Hubbard parameter calculations to investigate Co2ZrPb, a compound with potential for space energy applications. Energy gap assessments are conducted using GGA and mBJ-GGA methods. The study also analyzes the optical behavior of the compounds, including infrared and ultraviolet absorption. The BoltzTraP code is used for thermoelectric investigations, revealing a P-type charge carrier predominance in Co2ZrPb. This comprehensive approach provides valuable insights into electrical conductivity and thermoelectric properties.

Investigating the multifaceted characteristics of Ba2FeWO6 double perovskite: Insights from density functional theory.

This study undertook a comprehensive examination of the double perovskite complex Ba2FeWO6, investigating its structural, electrical, magnetic, thermal and elastic characteristics. The study used density functional theory (DFT), specifically the full potential linearized augmented plane wave (FP-LAPW) method. It also used different approximations, including the generalized gradient approximation (GGA) and the modified Trans-Blaha (TB-mBJ) approach, to improve the accuracy of the band gap estimation more accurate. Additionlly, the GGA + U approach, incorporating the Hubbard correction term (U), was utilized. Our findings indicate that Ba2FeWO6 exhibits indirect half-metallic band gaps in the (L-X) direction, with value of 0.91 eV and a net magnetic moment of 4 µB, predominatly influenced by the iron atom. The compound demonstrated exceptional characteristics suitable for thermoelectric applications, particularly at lower temperatures. Furthermore, the elasticity analysis revealed low brittleness, facilitates its manipulation in manufacturing procedures.