Theoretical investigation of phonon modes related to first Brillouin zone centre and properties of double perovskites Ba2MWO6 (M=Mg, Zn, Cd)

In this research work, we investigate phonon modes related to the first Brillouin zone centre of double perovskites Ba2MgWO6, Ba2ZnWO6, and Ba2CdWO6. Besides, Debye temperature, elastic constants, and elastic properties are also evaluated. These investigations are carried out by employing a theoretical model based on the six parameters bond-bending force constant. From our calculations, we found the strength of the first-neighbor interaction is higher as compared to the second and third neighbor's interatomic interactions. Our computed results corresponding to Young, Bulk, and Shear moduli and Debye temperature are found in a sequence Ba2CdWO6>Ba2ZnWO6>Ba2MgWO6. Moreover, all the examined double perovskite compounds reveal their ductile and elastically anisotropic nature. Our predicted results for frequencies of zone-centre phonons and elastic constants also show nice agreement with previously reported results.