Collect. Czech. Chem. Commun. 2008, 73, 1314-1326

Interaction of Niobium with Polycrystalline Palladium Surface. X-ray Photoemission Study

Ivan Jirka* and Zdeněk Bastl

J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, v.v.i., Dolejškova 3, 182 23 Prague 8, Czech Republic


Evolution of niobium-palladium (Nb-Pd) interface alloy prepared by in situ Nb deposition on highly defect polycrystalline Pd surface at room temperature has been investigated using X-ray photoelectron spectroscopy. The binding energies of the Nb 3d5/2 and Pd 3d5/2 core-level lines and their line shapes and the kinetic energies and shapes of Pd M4,5N4,5N4,5 Auger spectrum have been used to characterize the Nb-Pd system. A two-step growth mode of the Nb adlayer has been observed: a two-dimensional (2D)-like growth in a submonolayer Nb concentration region and three-dimensional (3D) intermixing of Nb and Pd atoms at Nb loadings above the monolayer coverage. The latter growth mode resulted in appearance of rather homogeneous Nb-Pd alloy phase.

Keywords: Auger spectrum; X-ray photoelectron spectroscopy; Polycrystalline surfaces; Monolayers; Nb-Pd surface alloy; Nb growth mode; XPS.

References: 20 live references.