Dresden 2014 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 55: Poster II
MA 55.82: Poster
Freitag, 4. April 2014, 10:30–13:30, P2
Electronic strcuture, magnetism and chemical bonding in hydrides of transition metal — •Abdesalem Houari1 and Volker Eyert2 — 1Theoretical ḧyics Laboratory, Dpt. Phyics, University of Bejaia, Bejaia, Algeria — 2Center for Electronic Correlations and Magnetism, Institut für Physik, Universität Augsburg, 86135 Augsburg, Germany
Based on density functional theory calculations, we present an ab initio study of the structural stability of the palladium-hydrogen (Pd-H) and platinum-hydrogen systems. Here, we first investigate two ideal stoichiometries: the monohydride Pd (Pt)1H1 and dihydride Pd (Pt)1H2. The formers was considered in different types of structures (faces centered cubic fcc-rocksalt, fcc-zincblende, and hexagonal symmetry), while the latters was considered in two cubic ones which are fluorite and pyrite. Energy versus volume calculations were carried out in all structures and theoretical equilibrium properties (lattice constant, bulk modulus ...etc) are thus obtained. By evaluating and comparing total energies, the ground state crystal structure is found, and it agree with the experimental finding. While the monohydride is energetically more stable than dihydride in Pd-H, the inverse is expected in Pt-H. On the other hand, the whole systems are found to be non magnetic at theoretical equilibrium. We have studied some experimentally synthesized vacancy-defect phase such as Pd3H4 compound. The obtained results (equilibrium lattice constant) are in perfect agreement with experimental