The Effect of H on the Electronic Structure of a Fe(110)-Pd(100) interface

ESTELA ANDREA GONZALEZ; JASEN, PAULA VERÓNICA; NAGEL OSCAR,; JUAN ALFREDO,

SURFACE REVIEW AND LETTERS

WORLD SCIENTIFIC PUBL CO PTE LTD

Año: 2003 vol. 10 p. 879 - 888

0218-625X

 The ion-driven mechanism in the hydrogen permeation is substantially modified when iron is coated with Pd. A detailed knowledge of the electronic structure at the metal-metal interfaces, is a pre-requisite to understand the H permeation process. We have selected two low Miller index surfaces as a simple model for the interface. The system under consideration has 148 metallic atoms forming a Fe-Pd cluster distributed in six metallic layers.We have investigated the interaction of atomic hydrogen with the Fe(110)-Pd(100) interface using the semi-empirical Atom Superposition and Electron Delocalization (ASED-MO) method. The changes in the electronic structures, density of states (DOS) and crystal overlap orbital population (COOP) in two different Fe-Pd interfaces were compared with the bulk ground states of both metals.The interfacial Fe-Pd distance result to be about 1.74 Å, whereas Fe-Pd first neighbors distance 1.85 Å. An important conclusion is that the metal-metal bonds at the interface are stronger than those bonds in the pure metal bulk. A favourable metal-adhesion is observed as revealed by the energetic stabilization of the composite metal system.H is stabilized near the FePd interface and stopped at the first Pd layer. A H-metal bond is developed with both Fe and Pd atoms while Fe-Pd bonding at the interface remains unaltered.