Investigating the Effect of Externally Applied Stress on the Structural, Optical, and Mechanical Properties of CsBeF ₃

ABSTRACT

This study investigated the impact of externally applied stress on the structural, electronic, optical, mechanical, and thermodynamic properties of the perovskite material CsBeF ₃ . Using computational simulations across a stress range of 0 to 100 GPa, we analyzed response of the material to compression. Structural evaluations revealed a uniform decrease in the lattice parameters and volume, as corroborated by x‐ray diffraction (XRD) analysis. Electronically, the bandgap widens significantly, a modification confirmed by the density of states and electron energy loss spectroscopy (EELS). Consequently, the optical properties, including the absorption, conductivity, and dielectric function, exhibited notable stress‐dependent shifts. Mechanically, the material demonstrated enhanced stiffness and resistance to deformation, as evidenced by the increased elastic constants and macroscopic moduli, as well as stress‐induced alterations in ductility and brittleness. Thermodynamically, the applied stress modifies the enthalpy, free energy, entropy, and Debye temperature, whereas the phonon dispersion analysis confirms the stiffening of the lattice vibrations. These findings provide a comprehensive theoretical framework for understanding the stress‐tunable characteristics of CsBeF ₃ , offering valuable insights into its potential integration into high‐pressure optoelectronic and photonic devices.