Structural, elastic, electronic and optical properties of double perovskites Ba2NaXO6 (X = Cl, Br, I): First-principles study

New findings on a Zintl phased K3Ag3As2 ternary semiconductor compound for photovoltaic applications by first-principles methods

“…The complex dielectric function is a frequency-dependent parameter used in analysing the optical response, and it is composed of two parts related to each other by the eqn (3). 28,29,36–38 ε ( ω ) = ε 1 ( ω ) + jε 2 ( ω )where ε 1 ( ω ) = n 2 ( ω ) − k 2 ( ω ) is the real part, while ε 2 ( ω ) = 2 nk is the imaginary part of the dielectric function, with n and k being the refractive index and extinction coefficient, respectively. ε 1 ( ω ) represents the dispersion of the incident photon by the material, and ε 2 ( ω ) represents the energy absorption by the material and relates to the optical transition from the valence band to the conduction band of a semiconductor material.…”

“…The complex dielectric function is a frequency-dependent parameter used in analysing the optical response, and it is composed of two parts related to each other by the eqn (3). 28,29,[36][37][38]…”

First-principles investigation of the structural stability, electronic, and thermodynamic properties of Ba2NaHaO6 (Ha = Cl, Br, I) periodate double perovskites

“…Wu et al also studied these crystal structures and found the band gaps using the PBE potentials to be 2.3820, 0.6158, and 0.6235 eV for Ba 2 NaIO 6 , Ba 2 NaBrO 6 , and Ba 2 NaClO 6 , respectively. 47 Kazim et al reported the band gap of Ba 2 NaIO 6 as 3.2 eV with modified Becke–Johnson (mBJ) potentials. 40 Further, Mir et al reported the GGA + mBJ computed band gaps of similar cubic Ba 2 FeNiO 6 and Ba 2 CoNiO 6 DP oxides as 1.66 eV and 1.22 eV, respectively.…”

“…54 Our results reasonably agree with previous investigations. 36,38,40,41,47 In the listed structural properties, the Ba 2 NaIO 6 structure is observed to possess a higher bulk modulus, estimated from the curve tting, which means it is harder and brittler, as also reported by Wu et al 47 However, the values of q D of Ba 2 NaBrO 6 and Ba 2 NaIO 6 structures are almost equal (i.e., 448.23 K and 448.25 K respectively) in our calculation, implying they have similar rigidity. In contrast, Wu et al reported a Debye temperature of 403.0 K and 411.8 K for the two structures, respectively.…”

“…, Ba 2 NaXO 6 (X = Cl, Br, I), and investigated the structural, electronic, elastic, and optical properties and accentuated their scope in optoelectronic devices. 47 Inspired by these investigations, our interest developed in exploring the phase stability and thermodynamic stability of these barium-based periodate DP oxides, which have not been studied before and which are equally important in compliment to their optical and thermoelectric properties and necessary to better comprehend their behavior under varying pressure and temperature conditions. 48–50…”