Atomic mechanisms for the diffusion of Mn atoms incorporated in the Cu(100) surface: an STM study

Flores, T.; Junghans, S.; Wuttig, Matthias

doi:10.1016/s0039-6028(96)00978-8

Cited by 46 publications

(9 citation statements)

References 25 publications

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“…Our observations clearly demonstrate that the findings for Cu and Ag under UHV conditions, i.e., the highly dynamic state of the atomic surface layer at room temperature, ,,− are also valid for electrochemical interfaces despite or perhaps precisely because of the presence of chemisorbed ions. A particularly interesting open question is whether similar behavior may occur for other chalcogens, especially oxygen.…”

supporting

confidence: 73%

“…The latter’s slow diffusion can be perfectly described by a simple random walk with jumps between neighboring sites, as evidenced by Poisson-like jump distributions. This is not the case for S ss diffusion: While some of the S ss remain at or close to their original location, others perform long jumps of up to 50 Å in just 0.2 s. The latter behavior closely resembles the vacancy-mediated diffusion mechanism observed by UHV-STM for various metal atoms embedded in Cu(100) and Cu(111) surfaces. − Here, multiple encounters with fast moving vacancies in the metal surface layer lead to a sequence of rapid displacement events (“slide puzzle motion”), manifesting as a sudden long-jump in the STM experiments. Because this vacancy-mediated diffusion primarily depends on the presence of highly mobile vacancies, it should also be possible for S ss at electrochemical interfaces.…”

mentioning

confidence: 88%

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Formation and Diffusion of Subsurface Adsorbates at Electrodes

Rahn

Magnussen

2018

J. Am. Chem. Soc.

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We report direct observation of the formation of a subsurface species at metal electrodes in liquid electrolytes and of its migration within the solid's surface layer, below a chemisorbed electrochemical double layer. Using in situ video-rate scanning tunneling microscopy, we find for adsorbed sulfide on bromide-covered Ag(100) electrodes reversible transitions between adsorption sites on top of the surface and within a vacancy in the first Ag layer. In the latter state, the sulfide surface diffusion can be enhanced by orders of magnitude, which we attribute to vacancy-mediated diffusion underneath the bromide adlayer. The high dynamics within the surface layer, indicated by these observations, may open up alternative pathways in electrocatalytic reactions and growth processes.

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supporting

confidence: 73%

mentioning

confidence: 88%

Formation and Diffusion of Subsurface Adsorbates at Electrodes

Rahn

Magnussen

2018

J. Am. Chem. Soc.

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“…A more precise comparison would be facilitated by experiments performed using ClO 4 - , BF 4 - , or some other anions that exhibit weak adsorption on copper. Similarly, in the last two years significant theoretical and experimental methods for quantifying defect generation and the role of steps in the kinetics of two-dimensional alloy formation − have been described and the extension of these studies to electrochemical systems should be fruitful.…”

Section: Discussionmentioning

confidence: 99%

Oxidative Chloride Adsorption and Lead Upd on Cu(100): Investigations into Surfactant-Assisted Epitaxial Growth

Moffat

1998

J. Phys. Chem. B

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The influence of chloride adsorption and lead upd on the step dynamics of Cu(100) has been examined in acid perchlorate solution. A c(2 × 2) Cl adlayer is formed upon immersion of a Cu(100) electrode leading to step faceting in the 〈100〉 direction. At more negative potentials an order−disorder transformation occurs leading to significant rearrangement of the steps. Alternatively, in an electrolyte containing Pb2+ the halide adlayer may be completely displaced by lead upd. Images of orthogonal surface steps in combination with an assessment of the coulometry suggest that the lead adlayer forms either a highly defective c(2 × 2), c(5√2 × √2)R45° or a disordered structure corresponding to a coverage ranging from 0.5 to 0.6. The transformation from the halide to the lead adlayer results in the formation of vacancies and adatoms which condense to form holes and islands, respectively. These features may be rationalized by the formation of an alloy phase at low coverage, which subsequently dealloys as the coverage approaches 0.5. The extent of the morphological changes associated with the alloying/dealloying processes is strongly path dependent. Voltammetry reveals that the stripping of the lead upd layer is associated with two oxidation waves. As the potential is increased beyond the peak of the first wave islands disappear which may be due to alloy formation occurring coincident with partial desorption of the lead. The second wave is associated with the nucleation 〈100〉-oriented rows of the c(2 × 2) Cl adlayer which propagate across the terraces displacing the lead phase. The use of metal upd and anions as surfactants in the electrochemical deposition of copper is likely to prove even more interesting than in vacuum deposition since the surfactant coverage and its effect on mesoscopic structure can be continuously manipulated by potential control.

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“…Vacancies have been invoked in the past to explain the incorporation of foreign atoms into a surface [18][19][20] or the ripening of adatom islands [21]. The vacancy-mediated diffusion mechanism of embedded atoms was first proposed for the motion of Mn atoms in Cu(001) during the formation of a surface alloy [22,23]. Our STM investigation of the diffusion of indium atoms embedded within the first layer of a Cu(001) surface was the first to prove unambiguously that this motion takes place with the help of surface vacancies [13,14].…”

Section: Vacancy-mediated Surface Diffusionmentioning

confidence: 99%

Vacancy diffusion in the Cu surface I: an STM study

et al. 2002

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We have used the indium/copper surface alloy to study the dynamics of surface vacancies on the Cu(0 0 1) surface. Individual indium atoms that are embedded within the first layer of the crystal, are used as probes to detect the rapid diffusion of surface vacancies. STM measurements show that these indium atoms make multi-lattice-spacing jumps separated by long time intervals. Temperature dependent waiting time distributions show that the creation and diffusion of thermal vacancies form an Arrhenius type process with individual long jumps being caused by one vacancy only. The length of the long jumps is shown to depend on the specific location of the indium atom and is directly related to the lifetime of vacancies at these sites on the surface. This observation is used to expose the role of step edges as emitting and absorbing boundaries for vacancies.

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Atomic mechanisms for the diffusion of Mn atoms incorporated in the Cu(100) surface: an STM study

Cited by 46 publications

References 25 publications

Formation and Diffusion of Subsurface Adsorbates at Electrodes

Formation and Diffusion of Subsurface Adsorbates at Electrodes

Oxidative Chloride Adsorption and Lead Upd on Cu(100): Investigations into Surfactant-Assisted Epitaxial Growth

Vacancy diffusion in the Cu surface I: an STM study

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