Time‐of‐flight atom‐probe field ion microscope studies of surface‐related phenomena

Abstract

The time-of-flight atom-probe field ion microscope is both a single-atom detection sensitivity mass-tocharge ratio analyser and an ion energy analyser, provided that the instrument resolution is good enough. Its major applications are in material analysis. However, it has been used also for studying surface-related phenomena such as surface segregation of alloys, mechanisms of ion formation in field desorption, novel ion and cluster ion formation in laser-stimulated field ion emission, field dissociation of compound ions and its novel isotope effects and analysis of the site-specific binding energy of surface atoms, etc. Some of these studies are briefly reviewed here.

Photon‐induced field desorption of NO from Rh

“…is even evidence for a field dependent (FD) neutralization. The analysis of the ESFD of 22 Ne and 20 Ne revealed that below 4.5 V/Å the heavier 22 Ne is less abundant than expected from the natural isotopic abundance of 8.8%. 18 Owing to its higher mass, this isotope stays longer in the re-neutralization zone and therefore has a higher probability of being quenched.…”

“…To elucidate the reason for this weak binding of NO at the Rh surface, an analysis by laser-induced field evaporation was performed. 21,22 At 2.5 V/Å and 20 J/cm 2 , a spectrum of surface species was obtained as shown in Fig. 10.…”

Um Problema de Interferência Quântica em Nanoestruturas Metálicas

“…Foi observado por Tsong e colaboradores o aparecimento de um comportamento oscilatório na composição de ligas próximo à superfície como, por exemplo, em ligas metálicas do tipo Pt-Rh e Pt-Ni, em que as composições do Rh e do Ni variam plano a plano, a partir da superfície, de forma decrescente em relação à concentração do volume [20,21].…”