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Sun Y, Zangari G. Observation of Weibull, Lognormal, and Gamma Distributions in Electrodeposited Cu and Cu-Ag Particles. MATERIALS (BASEL, SWITZERLAND) 2023; 16:6452. [PMID: 37834589 PMCID: PMC10573702 DOI: 10.3390/ma16196452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/15/2023] [Accepted: 09/25/2023] [Indexed: 10/15/2023]
Abstract
In this work, the nearest-neighbor distances and Voronoi cell features of Cu-Ag deposits were analyzed and fitted with Lognormal, Weibull, and Gamma distributions. The nearest-neighbor distance distributions of the samples were compared with those of complete spatially random points, showing spatial inhomogeneity due to the nucleation exclusion effect. The radial distribution function was calculated, showing both influences from the grain size and the nucleation exclusion effect. Voronoi cells were generated based on the shape of the grains. The size, occupancy, and coordination of the Voronoi cells were examined and fitted. The results show that although the Cu-Ag deposits seemed to be governed by the instantaneous nucleation mode, the spatial distribution of the nuclei was more impacted by the nucleation exclusion effect than the Cu-only samples. This behavior is also justified by the grain size distribution generated with Voronoi cell size and occupancy distributions.
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Affiliation(s)
- Yunkai Sun
- Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA 22904, USA
| | - Giovanni Zangari
- Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA 22904, USA
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Giurlani W, Biffoli F, Fei L, Pizzetti F, Bonechi M, Fontanesi C, Innocenti M. Analytic procedure for the evaluation of copper intermetallic diffusion in electroplated gold coatings with energy dispersive X-ray microanalysis. Anal Chim Acta 2023; 1269:341428. [PMID: 37290861 DOI: 10.1016/j.aca.2023.341428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 05/03/2023] [Accepted: 05/24/2023] [Indexed: 06/10/2023]
Abstract
A method for the determination of the intermetallic diffusion coefficient in the Cu-Au system is described based on energy dispersive X-ray techniques. XRF and EDS analysis were used to measure the thickness of the electroplated gold coating and the copper diffused through it, respectively. This information was used to obtain the diffusion coefficient through an equation based on Fick's law. Colour measurements and metallographic section analysis of the samples were also performed to evaluate alternative methods for a qualitative determination of diffusion rate. The thickness of the gold layer was chosen in agreement with what is used in decorative and functional applications (<1 μm). The measurements were performed on samples heated in a range of temperatures between 100 °C and 200 °C from 12 to 96 h. The results obtained follow a linear trend between the logarithm of the diffusion coefficient and the inverse of the temperature and are in line with the values found in the literature.
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Affiliation(s)
- Walter Giurlani
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019, Sesto Fiorentino, (FI), Italy; National Interuniversity Consortium of Materials Science and Technology (INSTM), Via G. Giusti 9, 50121, Firenze, (FI), Italy.
| | - Fabio Biffoli
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019, Sesto Fiorentino, (FI), Italy
| | - Lorenzo Fei
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019, Sesto Fiorentino, (FI), Italy
| | - Federico Pizzetti
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019, Sesto Fiorentino, (FI), Italy
| | - Marco Bonechi
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019, Sesto Fiorentino, (FI), Italy
| | - Claudio Fontanesi
- National Interuniversity Consortium of Materials Science and Technology (INSTM), Via G. Giusti 9, 50121, Firenze, (FI), Italy; Department of Engineering 'Enzo Ferrari', University of Modena and Reggio Emilia, Via Vivarelli 10, 41125, Modena, Italy
| | - Massimo Innocenti
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019, Sesto Fiorentino, (FI), Italy; National Interuniversity Consortium of Materials Science and Technology (INSTM), Via G. Giusti 9, 50121, Firenze, (FI), Italy; National Research Council-Organometallic Compounds Chemistry Institute (CNR-ICCOM), Via Madonna del Piano 10, 50019, Sesto F.no, (FI), Italy; Center for Colloid and Surface Science (CSGI), Via della Lastruccia 3, 50019, Sesto F.no, (FI), Italy.
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Electrochemical Synthesis of Nanocrystalline CuAg Coatings on Stainless Steel from Cyanide-Free Electrolyte. Processes (Basel) 2022. [DOI: 10.3390/pr10102134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Herein we demonstrate a novel plating bath, free from cyanide, to plate a highly adherent nanocrystalline copper-silver (ncCuAg) coating on a stainless-steel substrate and its application as an antimicrobial coating. The microstructures, such as the grain size, texture, microstrain, and the crystalline preferential orientation of CuAg deposits, are systematically investigated by X-ray diffraction analysis. The range of 13.4–16.6 nm was discovered to be the crystallite size determined from the X-ray peak broadening (Scherrer’s formula). Both HRTEM, FESEM-EDS, XPS, and mapping analysis revealed that the ncCuAg coatings are composed of both Ag and Cu atoms. Electrochemical processes occurring during CuAg co-deposition were investigated by using linear sweep voltammetry (LSV), cyclic voltammetry (CV), and anodic linear stripping voltammetry (ALSV). Additionally, the coatings made of ncCuAg produced by these baths work well as antibacterial agents against gram-positive (Staphylococcus) and gram-negative bacteria (Escherichia coli).
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Electrodeposition of Cu-Ag Alloy Films at n-Si(001) and Polycrystalline Ru Substrates. COATINGS 2021. [DOI: 10.3390/coatings11121563] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Electrodeposition of Cu-Ag films from acidic sulfate bath was conducted at n-Si(001) and polycrystalline Ru substrates. Significant nucleation overpotential of 0.4 V is observed with the Cu-Ag bath at n-Si(001) substrate, whereas the electrodeposition of Cu-Ag at Ru substrate is influenced by Ru oxides at the surface. Incomplete coverage of Si substrate by Cu-Ag deposit was observed from the deposition systems without Ag(I), or with 0.1 mM Ag(I), comparing with the compact Cu-Ag film obtained with the deposition bath containing 0.01 mM Ag(I). Layered and faceted Cu-Ag deposit was observed at small Cu deposition overpotential with the Ru substrate. Phase composition of the Cu-Ag deposits at n-Si(001) substrate from electrolyte with various Ag(I) concentrations is examined by XRD. Limited solubility of Ag (0.4 at.%) was observed in fcc-Cu until phase separation occurs. The classical model for nucleation kinetics in electrodeposition was used to examine the potentiostatic transients of the Cu-Ag electrodeposition at n-Si(001) substrate.
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