Oxidation of Gd-Ni composite and Gd cluster films grown on Ni(110) surfacestudied by photoemission

Soft X-ray synchrotron radiation photoemission (SRPES) and XPS were used to study the interaction of oxygen with Gd-Ni composite and Gd cluster films grown on Ni(110) surface. Different oxidation manners were found for the tw o kinds of films. Over the Gd-Ni composite film, the adsorption of oxygen r esulted in the segregation and oxidation of Gd component, and chemisorbed O - and lattice oxygen were detected. For the Gd cluster film, with the incre ase of oxygen exposure the oxidation states of Gd were developed between th e two peaks of the Gd4f double-peak at the expense of attenuation of HBE pe ak. Only one Ols XPS peak at 529.6 eV was detected in the range of 0-50 L e xposure. (C) 2001 Elsevier Science B.V. All rights reserved.