Abstract

Thermal programmed desorption (TPD) of hydrogen was performed in Pd and 5% Ru-Pd foils. The foils were inspected with Auger Electron Spectroscopy and Ar ion-sputter cleaned. Hydrogen dosage was 1000 L at 10(-3) Pa. Hydrogen evolving from Pd (TPD curves) was 12 times larger than for the 5% Ru-Pd foil. A 1.8 mu m thick Ru-Pd surface alloy was grown on the surface of Pd and the TPD curves were very similar to those of the 5% Ru-Pd bulk alloy. The lattice parameter of the Pd fcc crystal structure decreased by 2.8%, when alloying with 5% Ru. The lattice parameter of the fcc cell of Pd increased by 2.3% when absorbing hydrogen. Hydrogen saturation amount at 4655 Pa was obtained using a quartz crystal microbalance in a 24 nm Pd film and in a 5% Ru-Pd film. A hydrogen-metal ratio (x = H/Pd) was calculated from these measurements yielding a ratio of x(Pd) = 0.68 for Pd and x(RuPd) = 0.27 for similar to 2% Ru-Pd film. (C) 2013 Elsevier B.V. All rights reserved.