Investigation of stress-induced effects on structural, optoelectronic, and elastic characteristics of cubic CaHfO₃ perovskite oxide; A DFT study

Perovskite oxide being a fascinating class of perovskite materials, captured the significant attention of the scientific community in diverse fields due to its intriguing features. A cubic Calcium Hafnium Oxide (CaHfO3) perovskite supercell was designed using a DFT approach within the CASTEP framework with PBE-GGA approximation. The primary objective was to thoroughly investigate the effect of varying applied stress (0-160 GPa) on the structural, optoelectronic, and elastic characteristics in detail for appropriate device application. Findings reveal that with increasing stress levels, no phase transformation occurs, and cubic structure remains intact, as confirmed from the XRD profile, while a reduction in lattice parameters and volume of the unit cell is observed. Moreover, the optical analysis reveals the reduction in the band gap from 3.170 to 2.299, unveiling the narrow as the stress level rises. Additionally, optical characteristics showed that stress influences optical behaviour, resulting in low loss function, high absorption, high conductivity, and low reflectivity. The elastic constants and their derived parameters were investigated in this study. The results indicate that the material exhibits a ductile nature and anisotropy, as evidenced by Poisson's ratio, Cauchy pressure, and Frantsevich ratio. Notably, the mechanical stability of the material is maintained even as the stress level increases (0, 40, 80, and 120 GPa). These comprehensive findings contribute to a deeper understanding of stress-induced effects on perovskite oxides, offering valuable insights for their potential application and opening new avenues for experimental researchers by bridging the gap between theory and practical implementation for nextgeneration real practice in diverse fields.