Pattern formation during electrodeposition of copper-antimony alloys

Aim of the present study is to establish the conditions of the electrolysis for the preparation of structured and unstressed purple-pink coatings of copper-antimony alloys, including their phase characterization. Also the task of the present investigation is, by changing drastically the metal content in the methanesulfonic electrolyte to find out the conditions of electrolysis where the self-organization of the different phases is expressed by higher-order structures - not only waves but also spirals and targets. The possibility to obtain copper-antimony alloy with up to 80 wt. % Sb from methanesulfonic acid is shown. The deposition rate, morphology and the phase composition of the obtained coatings are established. The phenomena of formation of spatio-temporal structures in this alloy are described.It is determined that the observed structures consist of Cu2Sb and Cu11Sb3 intermetallic phases

Depth-Dependent Scanning Photoelectron Microspectroscopy Unravels the Mechanism of Dynamic Pattern Formation in Alloy Electrodeposition

Fascinating spatiotemporal patterns forming during the electrodeposition of some alloys have attracted the interest of the scientific communities dealing with electrochemical materials science and dynamic processes. Notwithstanding extensive experimental work and recently achieved theoretical insights, several aspects of the physical chemistry of these dynamic structures are still elusive. In particular, the analytical methods employed so far to characterize these structures invariably failed to pinpoint any chemical or structural patterns correlated to those perceived by the naked eye or with a light microscope. In this work, we have made systematic use of the extreme surface sensitivity provided by synchrotron-based scanning photoelectron microspectroscopy, combined with progressive erosion by precisely controlled Ar+ sputtering, to achieve quantitative 3D understanding of the compositional and chemical-state distribution of an Ag−In electrodeposited layer, following the key elements Ag, In, and O. The results revealed that the pattern is present only in the topmost region (ca. 100 nm) of the layer and exhibits a regular distribution of the alloying elements in certain chemical states. Specifically, pattern formation in Ag−In electrodeposits is crucially controlled by the space distribution of surface In3+ oxi-/ hydroxides, deriving from reaction-diffusion processes taking place during alloy growth, and this pattern disappears in depth because of the delayed reduction of In3+ present in this film to elemental In, followed by intermetallic formation

Depth-Dependent Scanning Photoelectron Microspectroscopy Unravels the Mechanism of Dynamic Pattern Formation in Alloy Electrodeposition

Fascinating spatiotemporal patterns forming during the electrodeposition of some alloys have attracted the interest of the scientific communities dealing with electrochemical materials science and dynamic processes. Notwithstanding extensive experimental work and recently achieved theoretical insights, several aspects of the physical chemistry of these dynamic structures are still elusive. In particular, the analytical methods employed so far to characterize these structures invariably failed to pinpoint any chemical or structural patterns correlated to those perceived by the naked eye or with a light microscope. In this work, we have made systematic use of the extreme surface sensitivity provided by synchrotron-based scanning photoelectron microspectroscopy, combined with progressive erosion by precisely controlled Ar⁺ sputtering, to achieve quantitative 3D understanding of the compositional and chemical-state distribution of an Ag–In electrodeposited layer, following the key elements Ag, In, and O. The results revealed that the pattern is present only in the topmost region (ca. 100 nm) of the layer and exhibits a regular distribution of the alloying elements in certain chemical states. Specifically, pattern formation in Ag–In electrodeposits is crucially controlled by the space distribution of surface In³⁺ oxi-/hydroxides, deriving from reaction-diffusion processes taking place during alloy growth, and this pattern disappears in depth because of the delayed reduction of In³⁺ present in this film to elemental In, followed by intermetallic formation