The investigation of stabilities of ZrMo2 and HfMo2 compounds with Ab-initio method

In study of this thesis, the structural, mechanical, electronic, and lattice dynamical properties of ZrMo2 and HfMo2 compounds in cubic C15 (space group Fd-3m), hexagonal C14 (space group P63/mmc), C36 (space group P63/mmc), and orthorhombic CeCu2 (space group Imma) structures have been investigated by using the first principles method based on density functional theory. We have found that these compounds in cubic C15 crystal structure are the most stable among the considered structures. From calculated elastic constants, it is shown that all structures are mechanically stable according to the elastic stability criteria. The related mechanical properties such as bulk, shear and Young moduli, Poisson's ratio, Debye temperature, hardness, and anisotropy have been also calculated and commented. The phonon dispersion curves and phonon density of states are also computed and discussed exhaustively for considered phases. The all compounds exhibit dynamical stability for except CeCu2 structure. The obtained results are in the agreement with the available-experimental-and-theoretical-results.