Search

For the first time, first-principles investigations using density functional theory (DFT) were thoroughly conducted on the structural, mechanical, optical, anisotropic, thermodynamic and electronic properties of TlCrX2 (X = S, Se) materials. The mechanical stability of both compounds is confirmed as their elastic constants satisfy the Born criteria. The bulk modulus, Poisson's ratio and shear modulus have been utilized to investigate the mechanical stability of this compound. The comparisons of the elastic moduli show a significant correlation with previously obtained experimental data. Notably, TlCrSe2 transitions from brittle to ductile when Se is substituted with S, improving its machinability for industrial uses. TlCrSe2 is characterized by its softness, ductility, high machinability, and exceptional dry lubricity. Additionally, these materials display anisotropy. The melting temperature, phonon thermal conductivity, and Debye temperature of TlCrX2 (X = S, Se) are low, while the compound shows a moderate Grüneisen parameter. TlCrX2 compounds exhibit moderate Debye temperatures, low melting points, and Grüneisen parameters, indicating their potential use in thermal barrier coatings. In addition, an in-depth optical evaluation reveals that these compounds hold promise for use in electronic and optoelectronic devices. Both materials exhibit a high refractive index at low energy levels, including the visible spectrum, and uniform reflectivity across a wide range of photon energies. TlCrX2 (X = S, Se) exhibit high UV absorption, making them excellent candidates for UV-related applications, such as surgical equipment disinfection, photovoltaic materials for X-ray phosphors, space technology and solid-state LED lighting. Their high reflectivity in the visible range suggests potential as efficient solar reflectors to minimize solar heating, while low reflectivity at higher energies (above 15 eV) and a high refractive index at low photon energies highlight their suitability for optoelectronic devices, including LEDs. These properties underscore their versatility for advanced optical and electronic applications. [ABSTRACT FROM AUTHOR]

For the first time, we have reported in this study an ab initio investigation on elastic properties, Debye temperature, Mulliken population, Vickers hardness, and charge density of the two recently synthesized superconducting ScRhP and ScIrP pnictides. The optimized cell parameters show fair agreement with the experimental results. The mechanical stability of both ternary phosphides is confirmed via the calculated elastic constants. Both compounds are ductile in nature and damage tolerant. ScIrP is expected to be elastically more anisotropic than ScRhP. The estimated value of Debye temperature predicts that ScRhP is thermally more conductive than ScIrP and the phonon frequency in ScRhP is higher than that in ScIrP. Both pnictides are soft and easily machinable due to their low Vickers hardness. Moreover, the hardness of ScRhP is lower due to the presence of antibonding Rh-Rh in ScRhP. The metallic conductivity of ScRhP reduces significantly when Rh is replaced with Ir. The main contribution to the total density of states (TDOS) at Fermi-level ( EF) comes from d-electrons of Sc and Rh/Ir in both pnictides. These two ternary compounds are characterized mainly by metallic and covalent bonding with little ionic contribution. The calculated superconducting transition temperatures fairly coincide with the reported measured values. [ABSTRACT FROM AUTHOR]