Under Pressure DFT Investigations on Optical and Electronic Properties of PbZrO₃

Abstract

In this article, density functional theory has been used to investigate the structural and optoelectronic properties of PbZrO3 (PZO) under pressure from 0 to 350 GPa. In order to achieve ground state structural stability, generalized gradient approximations has been utilized. By studying electronic properties, indirect band-gap nature of PZO appears to change at 15 GPa to direct band-gap. Optical analysis include under pressure responses of real and imaginary parts of dielectric function, optical conductivity, optical absorption coefficient, energy loss function, refractive index, reflectivity and extinction coefficient. Most of the results have been found to be consistent with literature. Study reveals that static dielectric constant and band-gap are in accordance with the Penn model which validates our computed results. Moreover, static dielectric constant and static refractive index directly increases with pressure. Material preserves its positive value of refractive index at all pressures and therefore, it is not a negative index metamaterial. Plasma frequency increases directly with pressure that destabilize the under study material. Our results could be very useful for developing novel optoelectronic devices based on PZO suitable to work under extreme conditions.

Structural, electronic, mechanical and optical properties of K2CuX (X=As, Sb) Ternary Compounds

“…The necessary and sufficient conditions for elastic stability of the orthorhombic crystal system [27], [28] are given as; The computed elastic constants in table 3 satisfy the conditions for elastic stability of the orthorhombic system; thus, the K 2 CuAs and K 2 CuSb ternary compounds are mechanically stable. The restriction for brittleness is B/G < 1.75; otherwise, the material is said to have a ductile behavior [18], [29], [30]. The B/G values obtained in this investigation are 2.05 and 2.17 for K 2 CuAs and K 2 CuSb respectively.…”

“…The photon transmission persisted until the energy regions of 5-7 eV where the electromagnetic spectrum became damped. All the other optical constants including the absorption coefficients α (ω), refractive index n (ω), extinction coefficient K(ω), reflectivity R (ω), and energy loss function L (ω) were computed using the equations [15], [32], [36], [37]; The calculated refractive indices for K 2 CuAs and K 2 CuSb were 2.49 and 2.54 respectively. The major refractive index peaks reside within the visible region.…”

First-Principle Calculations to Investigate Structural, Electronic, Elastic, Mechanical, and Optical Properties of K2CuX (X=As, Sb) Ternary Compounds

“…e ductile (ionic) and brittle (covalent) nature of materials is determined by using Pugh's ratio B/G and Poisson's ratio, n [62]. e restriction for brittleness is B/ G < 1.75; otherwise, the material is said to be ductile [63].…”

“…where ε 1 (ω) and ε 2 (ω) refer to the real and imaginary parts of the complex dielectric wave function. All the other optical constants including the absorption coefficients α (ω), refractive index n (ω), extinction coefficient K(ω), reflectivity R (ω), and energy loss function L (ω) presented in Figure 5 are computed by using the equations presented as follows [41], [63,68,69]:…”

Quantum density functional theory studies of structural, elastic, and opto-electronic properties of ZMoO3 (Z = Ba and Sr) under pressure

“…In the first step, optimized lattice constants of the cubic oxide-perovskite BaMoO 3 and SrMoO 3 are calculated at 0 GPa with values 4.039 Å and 3.999 Å, respectively, which are reported in the previous literature. [26] The obtained data at 0 GPa was then used in the equation [43]…”