Palladium nanojunctions in hydrogen environment: a theoretical study

S. C. GÓMEZ-CARRILLO; M. A. ROMERO; P. G. BOLCATTO; E. C. GOLDBERG

San Carlos de Bariloche, Argentina

Congreso; 13th International Conference on Solid Films and Surfaces; 2006

The interaction of hydrogen with the atomic-sized contact is an specially interesting problem for Pd junctions, as Pd is highly reactive with respect to H2. It has been found that the conduction in Pd-H system has a more complex behavior than in Pt-H2, and it has been attributed to the dissolution of hydrogen in the electrodes. Two atomic configurations are proposed for explaining the conductance value found experimentally G = 1G0. The firstone is a single-atom Pd between Pd-H electrodes. The second possibility is the Pd2H2 complex similar to what was proposed for platinum junctions. In this work we calculate the transport properties of the first atomic configuration by using the own-developed bond-pair model to describe the atom-surface interaction. A Green function formalism is used for calculating the electronic transport, being explored different contact geometries. In this way the effect of the d-orbital directionality is analyzed.