Pb UPD on Ag(100) and Au(100) — 2D phase formation studied by in situ STM

We have investigated the structure and thermal dynamics of alkanethiolate layers on Au(lll) with variable temperature scanning tunnelling microscopy (STM), X-ray photoelectron spectroscopy (XPS) and voltammetry. The results build the basis for a study of electrodeposition of copper on alkanethiolate-covered Au(lll). Electrodeposition has been studied as a function of the thiolate chain length, the deposition potential and the temperature. Time-resolved [1][2][3][4][5][6][7].

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“…In the UPD range where island formation on bare metal substrates is a rare phenomenon (but see [37] and [38] [29].…”

Section: Thiolate Layers and The Electrodeposition Of Metalsmentioning

confidence: 99%

“…Further growth proceeded either not or extremely slowly at less than 0.7 nm in two hours. Apart from the fact that island formation in the UPD range is a rare phenomenon (but see [37] and [38] [80].…”

Section: Thiolate Layers and The Electrodeposition Of Metalsmentioning

confidence: 99%

Copper Electrodeposition on Alkanethiolate Covered Gold Electrodes*

Cavalleri¹,

Bittner²,

Kind³

et al. 1999

Zeitschrift Für Physikalische Chemie

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“…On the other hand, in situ STM studies on the UPD process that involves surface reconstruction are very limited in systems and at depth, 6,7 and studies on underpotential alloying are quite rare. This situation is mainly due to the complexity of the alloying process and the concern to avoid the risk of single-crystal damage when running into the alloying stage, but the consideration that underpotential alloying should be more or less placed in a different category of UPD also plays a negative role.…”

Section: Introductionmentioning

confidence: 99%

In situ STM studies on underpotential deposition of Sn on Au(100)

Yan

Tang

Yang

et al. 2001

Surface & Interface Analysis

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We present in situ STM studies on Sn electrodeposition on Au(100) surfaces at underpotentials. The Sn under potential deposition (UPD) on Au(100) proceeds in three stages: the reversible submonolayer UPD; surface alloying; and alloying that extends to the bulk. The formation of the reversible submonolayer UPD proceeds in the form of clusters of similar to2 nm. at potentials as early as 0.04 V. The surface alloying takes place at -0.04 V, which is evidenced by sudden immersion of the Sn clusters as well as significant changes of steps on the surface. The bulk alloying sets in at -0.3 V, which leads to rapid change of the surface morphology. The earlier set in of the surface and bulk alloying process is considered the result of enhanced interdiffusion of Sn and Au atoms upon decreasing the potential. It has been shown that Sn UPD on Au(100) is much more complex than that of other metal UPD systems studied previously by electrochemical scanning tunnelling microscopy, but it serves as a good system for all-sided studies of the UPD processes. Copyright (C) 2001 John Wiley & Sons, Ltd

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“…In a more recent article, Carnal et al [78] reported STM images showing the border of an "incomplete" Pb monolayer, coexisting with a nacked Ag(111) surface. For the second of these systems, Schmidt et al [157] found decoration of steps of the Ag(100) surface, with the subsequent formation of 2D Pb islands at lower potentials. Also step decoration has been found in the case of Tl upd on Ag(111) [78], thus indicating the formation [24,67,86], but no island formation was reported in these articles.…”

Section: ð3:54þmentioning

confidence: 97%

Phenomenology and Thermodynamics of Underpotential Deposition

Oviedo

Reinaudi

García

et al. 2015

Underpotential Deposition

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As can be found from the other chapters of this book, underpotential deposition shows a wide variety of behaviors, which involve the occurrence of several surface phases, formation of submonolayers, monolayers (ML) and eventually the formation of bilayers. Adsorption may be commensurate or incommensurate, where the ML may undergo compression, and metal adatoms may coadsorb with anions to generate new phases. To start the discussion and briefly go into the history of the development of thermodynamic models for upd, we consider a relatively "simple" system, as shown in Fig. 3.1, which corresponds to Ag deposition on Pt(111) [1]. The voltammogram of this system presents three cathodic and three anodic peaks, which correspond to ML formation/desorption(3), bilayer formation/desorption(2) and bulk deposition/oxidation(1) of Ag. The peak potentials of the complementary processes do not coincide, denoting that at the present sweep rate a quasi equilibrium state has still not been reached. For the discussion below, we choose the anodic peaks, that we will denote with E 1 , E 2 and E 3 (see Fig. 3.1). At the sight of the features of this voltammogram, and although the abscissa axis gives a measure for the electrochemical potential of electrons at the working electrode, it may be appealing to use the position of the peaks found for this system as a measure for the stability of the different upd ad-phases being formed. In this spirit, Kolb et al. [2][3][4] introduced in the 1970s the concept of underpotential shift, ΔE upd . This quantity was defined as the difference in the potential of the desorption peak for a layer of a metal M adsorbed on a foreign substrate S and the potential of the peak corresponding to the dissolution of the pure metal M. In the present case, ΔE upd ¼ E 3 À E 1 , as marked in the red segment in Fig. 3.1. At the time Kolb et al. developed their modeling of upd, single crystal surfaces were not available for performing electrochemical experiments, so that all the data employed by these authors were restricted to polycrystalline surfaces. On the basis

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Pb UPD on Ag(100) and Au(100) — 2D phase formation studied by in situ STM

Cited by 81 publications

References 52 publications

Copper Electrodeposition on Alkanethiolate Covered Gold Electrodes*

Copper Electrodeposition on Alkanethiolate Covered Gold Electrodes*

In situ STM studies on underpotential deposition of Sn on Au(100)

Phenomenology and Thermodynamics of Underpotential Deposition

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