Investigation of structure and elastic properties ofXYF3 (X=Ag, K and Y=Mg, Ni, Zn, Co, Mn) theoritically

Fluoride Perovskites with the general formula ABF3 (A: Alkali metals, B: Alkaline earth metals) have received great attention because of their interesting properties such as photoluminescence, piezoelectricity, ferromagnetism and magnetoresistivity. These unique properties of ABF3 compounds make them favorable materials to use in optical applications, lenses, magnetic tunnel junctions and medical applications. However, in order to determine whether a material can be used in technological or industrial applications, it is necessary to know especially its elastic and mechanical properties. The structural and elastic properties of XYF3 (X=Ag,K and Y=Mg, Ni, Zn, Co, Mn) compounds have been calculated by using generalized gradient approximation within the density functional theory in this thesis. The calculated lattice parameters of studied compounds have been found in good agreement with the corresponding experimental results. Additionally, the shear modulus, Young's modulus, Poisson's ratio, Kleinman parameter, elastic anisotropic factor and Lame's coefficients for all studied compounds are also calculated and discussed in detail. Besides, the ductile and brittle characters of the studied compounds have been determined using B/G ratio and Poisson's ratio.