First principles study of elastic and acoustic properties of new chloride perovskites

The materials with a perovskite phase have been in the limelight due to their power conversion efficiency (PSC) in solar cells. New perovskite materials are essential to predict the abundant availability of efficient materials for technological applications. Mechanical properties can predict the mechanical stability of crystals. Therefore, it is very important to know their mechanical parameters. So, in this work, the elastic constants C11, C12 and C44 of the cubic chloride perovskites (ABCl3) have been determined through first principles study using density functional theory by using the Chirpan method integrated with WIEN2k. After calculating the elastic constants, we have also calculated different moduli like Shear, Bulk and Young moduli, different parameters like Kleinman’s constant, Lame constants, Chung–Buessem anisotropy index, universal anisotropic index, acoustic behavior and its anisotropy, hardness, melting temperature, Poisson ratios by using different formulas in connection with the elastic constants. It has been found that the studied compounds possess low resistance to the plastic deformations. It has also been found that the majority of the materials possess a central type of force because Poisson’s ratio is greater than 0.25. It has been studied that six out of eighteen new perovskites were brittle and the rest were ductile. The anisotropy of the materials was checked and found that all the materials are anisotropic elastically. This work is useful for the synthesis of these new perovskites.