title: Redox processes at a nanostructured interface under strong electric fields.
abstract: Manipulation of chemistry and film growth via external electric fields is a longstanding goal in surface science. Numerous systems have been predicted to show such effects but experimental evidence is sparse. Here we demonstrate in a custom-designed UHV apparatus that the application of spatially extended, homogeneous, very high (>1 V nm(-1)) DC-fields not only changes the system energetics but triggers dynamic processes which become important much before static contributions appreciably modify the potential energy landscape. We take a well characterized ultrathin NiO film on a Ag(100) support as a proof-of-principle test case, and show how it gets reduced to supported Ni clusters under fields exceeding the threshold of +0.9 V nm(-1). Using an effective model, we trace the observed interfacial redox process down to a dissociative electron attachment resonant mechanism. The proposed approach can be easily implemented and generally applied to a wide range of interfacial systems, thus opening new opportunities for the manipulation of film growth and reaction processes at solid surfaces under strong external fields.
authors: Surface and Interface Physics, Institute of Physics, Karl-Franzens University Graz, A-8010 Graz, Austria.
authors: Wolfram
authors: W
authors: Steurer
authors: Svetlozar
authors: S
authors: Surnev
authors: Falko P
authors: FP
authors: Netzer
authors: Luca
authors: L
authors: Sementa
authors: Fabio R
authors: FR
authors: Negreiros
authors: Giovanni
authors: G
authors: Barcaro
authors: Nicola
authors: N
authors: Durante
authors: Alessandro
authors: A
authors: Fortunelli