A. K. Santra

Surface alloy formation in Pd/Ag, Cu/Au and Ni/Au bimetallic overlayers

X-ray and UV photoemission along with Auger spectroscopic studies show the formation of surface alloys in the Pd/Ag and Cu/Au overlayers on polycrystalline substrates. Surface alloy formation also occurs in the Ni/Au overlayers although Au and Ni do not form bulk alloys over the entire range of compositions.

An investigation of the Cu/ZnO/Zn system: evidence for the formation of Cu---Zn alloys by the inward diffusion of Cu

Abstract Cu deposited on 5 or 10 A thick ZnO layers (grown on Zn metal), has been investigated as a function of Cu coverage by employing X-ray photoelectron and Auger electron spectroscopies. The 2p core-level binding energy of Cu increases with decreasing metal coverage, the maximum shift observed (with respect to bulk Cu metal) at the smallest coverage being ∼ 0.9 eV. Temperature dependent studies show that Cu diffuses through the ZnO layer with the rate of diffusion varying with the substrate temperature as well as the oxide layer thickness. The inward diffusion of Cu results in the formation of CuZn alloys. Diffusion kinetic experiments at different temperatures show that the activation energy for diffusion increases with the increasing oxide layer thickness.

An investigation of bimetallic clusters by a combined use of electron microscopy and photoelectron spectroscopy: additive effects of alloying and cluster size on core-level binding energies

Bimetallic clusters of Ni-Pd, Cu-Ni, Cu-Au and Au-Ni deposited on amorphized graphite have been in- vestigated by a combined use of photoelectron spectroscopy and electron microscopy. Metal core-level binding energies (Pd 3d, Au 4f and Ni/Cu 2p) of the bimetallic clusters deposited on amorphized graphite have been measured for different coverages or mean cluster sizes. When the cluster is large, the core-level binding energy the major metallic component in the bimetallic clusters

Interaction of solid films of C60 and C70 with nickel

(e.g. \hspace{2mm} Cu\hspace{2mm} in\hspace{2mm} Cu_3Au \hspace{2mm} or \hspace{2mm} Cu_7Ni_3)

A comparative study of the interaction of nickel clusters with buckminsterfullerene, C60, and graphite

is close to that of the bulk metal while that of the minor component

Electronic structures and reactivities of monometallic and bimetallic clusters of Au and Cu

(e.g. \hspace{2mm} Au \hspace{2mm} in \hspace{2mm} Cu_3Au \hspace{2mm} or \hspace{2mm} Ni \hspace{2mm} in \hspace{2mm} Cu_7Ni_3)

A comparative study of the interaction of CO with Cu and Cu-Zn alloy clusters

shows the effect of alloying. The effect of alloying is found in the core-level energies of both Ni and Pd in the large clusters of

Investigations of the Interaction of Nickel and Carbon Monoxide with Solid Films of C60 and C70 by UV and X-Ray Photoelectron Spectroscopy

Ni_3Pd_2

Interaction of nitrogen and oxygen with C60

. With the decrease in cluster size or coverage, the core-level binding energies of both the metals increase, just as in the case of monometallic clusters. The present results show the occurrence of parallel shifts in the core-level binding energy of metals due to alloying and cluster size effects, both the effects manifesting themselves in the small clusters. It is noteworthy that the core-level binding energy shifts in bimetallic clusters are distinctly different from those in bimetallic overlayers. Although alloy formation does not occur in the Au-Ni system in the bulk, the

Interaction of nitrogen with fullerenes: nitrogen derivatives of C60 and C70

Au_3Ni