Pressure effect on the physical, mechanical, and thermal properties of ternary halide perovskite AgCaCl3: a first-principles study.

Context and results: As an inorganic halide perovskite material, AgCaCl₃, characterized by its high stability and environmental friendliness, is considered a potential candidate for major applications in optoelectronics and lens manufacturing. This work aimed to determine the electronic properties such as density of state (DOS) and band structure (BS) of AgCaCl3. The results showed that the material has an indirect band gap almost invariably at 1.5 eV in the pressure range studied. The dielectric function ε ω , absorption coefficient α (ω) , optical conductivity σ (ω) , reflectivity R (ω) , and the refractive index n (ω) showed clearly that the perovskite AgCaCl₃ preserved its optical characteristics within the chosen pressure range investigated. The calculated elastic constants C₁₁, C₁₂, and C₁₄ as dynamic stability criteria for the elastic moduli such as bulk modulus (B), shear modulus (G), Young's modulus (Y), Poisson's ratio (υ ), and anisotropy factor (A) showed that the material is a ductile plastic. Debye temperature (θ ), isobaric and isochoric heat capacities (C_P, C_V), coefficient of the thermal expansion (α), Gibbs free energy (G), and entropy (S) were also studied. The results obtained provide a theoretical basis for experimental work and offer the possibility of future industrial applications of AgCaCl₃. Computational and theoretical techniques: Density functional theory (DFT) calculations as implemented in the Wien2K code were used to study the mechanical and thermal properties of AgCaCl₃ perovskite over a pressure range. Lattice parameters, electronic, and optical properties are optimized with the approximation of the generalized gradient of the Perdew-Burke-Ernzerhof function (PBE-GGA) function. The mechanical and thermodynamic properties were calculated using ElaStic and Gibbs2 codes, and the properties of AgCaCl₃ over the pressure range investigated were predicted. [ABSTRACT FROM AUTHOR]