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Bogatyrenko SI, Kryshtal AP, Kruk A. Effect of Size on the Formation of Solid Solutions in Ag-Cu Nanoparticles. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2023; 127:2569-2580. [PMID: 36818666 PMCID: PMC9931174 DOI: 10.1021/acs.jpcc.2c07132] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 01/17/2023] [Indexed: 06/18/2023]
Abstract
Modern technologies stimulate the quest for multicomponent nanosized materials with improved properties, which are ultimately defined by the atomic arrangement and interphase interactions in the nanomaterial. Here, we present the results of the experimental study of the formation of solid solutions in Ag-Cu nanoparticles in a wide size and temperature range using in situ TEM techniques. The Ag-Cu nanoparticles with a eutectic ratio of components were formed on an amorphous carbon film by the physical vapor deposition technique. Electron diffraction, HAADF-STEM imaging, energy-dispersive X-ray spectroscopy, chemical element mapping, and electron energy loss spectral imaging were used for the characterization of mixing patterns and composition of phases in AgCu nanoparticles down to the atomic level. As a result, we constructed the solid-state part of the Ag-Cu phase diagram for nanoparticles with a size down to 5 nm. We found a highly asymmetric behavior of the solvus lines. Thus, the content of Cu in Ag gradually increased with a size reduction and reached the ultimate value for our configuration of 27 wt % Cu at a nanoparticle size below ∼8 nm. At the same time, no Cu-rich solid solution was found in two-phase AgCu nanoparticles, irrespective of the size and temperature. Moreover, a quasi-homogeneous solid solution was revealed in AgCu nanoparticles with a size smaller than 8 nm already at room temperature. A size dependence of the terminal temperature T term, which limits the existence of AgCu alloy nanoparticles in a vacuum, was constructed. Evaporation of the AgCu phase with the composition of 86 wt % Ag was observed at temperatures above T term. We show the crucial role of the mutual solubility of components on the type of atomic mixing pattern in AgCu nanoparticles. A gradual transition from a Janus-like to a homogeneous mixing pattern was observed in Ag-Cu nanoparticles (28 wt % Cu) with a decrease in their size.
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Affiliation(s)
| | - Aleksandr P. Kryshtal
- AGH
University of Science and Technology, Al. A. Mickiewicza 30, KrakówPL-30 059, Poland
| | - Adam Kruk
- AGH
University of Science and Technology, Al. A. Mickiewicza 30, KrakówPL-30 059, Poland
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2
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Nelli D, Pietrucci F, Ferrando R. Impurity diffusion in magic-size icosahedral clusters. J Chem Phys 2021; 155:144304. [PMID: 34654289 DOI: 10.1063/5.0060236] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Atomic diffusion is at the basis of chemical ordering transformations in nanoalloys. Understanding the diffusion mechanisms at the atomic level is therefore a key issue in the study of the thermodynamic behavior of these systems and, in particular, of their evolution from out-of-equilibrium chemical ordering types often obtained in the experiments. Here, the diffusion is studied in the case of a single-atom impurity of Ag or Au moving within otherwise pure magic-size icosahedral clusters of Cu or Co by means of two different computational techniques, i.e., molecular dynamics and metadynamics. Our simulations reveal unexpected diffusion pathways, in which the displacement of the impurity is coupled with the creation of vacancies in the central part of the cluster. We show that the observed mechanism is quite different from the vacancy-mediated diffusion processes identified so far, and we demonstrate that it can be related to the presence of non-homogeneous compressive stress in the inner part of the icosahedral structure.
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Affiliation(s)
- Diana Nelli
- Dipartimento di Fisica dell'Università di Genova, via Dodecaneso 33, Genova 16146, Italy
| | - Fabio Pietrucci
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, IMPMC, 75005 Paris, France
| | - Riccardo Ferrando
- Dipartimento di Fisica dell'Università di Genova and CNR-IMEM, via Dodecaneso 33, Genova 16146, Italy
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Mikkelä MH, Jänkälä K, Huttula M, Björneholm O, Tchaplyguine M. Free silver nanoparticles doped by potassium: Work-function change in experiment and theory. J Chem Phys 2021; 154:234708. [PMID: 34241256 DOI: 10.1063/5.0052101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The composition-dependent change in the work-function (WF) of binary silver-potassium nanoparticles has been studied experimentally by synchrotron-based x-ray photoelectron spectroscopy (PES) and theoretically using a microscopic jellium model of metals. The Ag-K particles with different K fractions were produced by letting a beam of preformed Ag particles pass through a volume with K vapor. The PES on a beam of individual non-supported Ag-K nanoparticles created in this way allowed a direct absolute measurement of their WF, avoiding several usual shortcomings of the method. Experimentally, the WF has been found to be very sensitive to K concentration: Already at low exposure, it decreased down to ≈2 eV-below the value of pure K. In the jellium modeling, considered for Ag-K nanoparticles, two principally different adsorption patterns were tested: without and with K diffusion. The experimental and calculation results together suggest that only efficient surface alloying of two metals, whose immiscibility was long-term textbook knowledge, could lead to the observed WF values.
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Affiliation(s)
| | - Kari Jänkälä
- Nano and Molecular Systems Research Unit, University of Oulu, 90014 Oulu, Finland
| | - Marko Huttula
- Nano and Molecular Systems Research Unit, University of Oulu, 90014 Oulu, Finland
| | - Olle Björneholm
- Department of Physics and Astronomy, Uppsala University, 75120 Uppsala, Sweden
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Eom N, Messing ME, Johansson J, Deppert K. General Trends in Core-Shell Preferences for Bimetallic Nanoparticles. ACS NANO 2021; 15:8883-8895. [PMID: 33890464 PMCID: PMC8291766 DOI: 10.1021/acsnano.1c01500] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 04/16/2021] [Indexed: 06/12/2023]
Abstract
Surface segregation phenomena dictate core-shell preference of bimetallic nanoparticles and thus play a crucial role in the nanoparticle synthesis and applications. Although it is generally agreed that surface segregation depends on the constituent materials' physical properties, a comprehensive picture of the phenomena on the nanoscale is not yet complete. Here we use a combination of molecular dynamics (MD) and Monte Carlo (MC) simulations on 45 bimetallic combinations to determine the general trend on the core-shell preference and the effects of size and composition. From the extensive studies over sizes and compositions, we find that the surface segregation and degree of the core-shell tendency of the bimetallic combinations depend on the sufficiency or scarcity of the surface-preferring material. Principal component analysis (PCA) and linear discriminant analysis (LDA) on the molecular dynamics simulations results reveal that cohesive energy and Wigner-Seitz radius are the two primary factors that have an "additive" effect on the segregation level and core-shell preference in the bimetallic nanoparticles studied. When the element with the higher cohesive energy also has the larger Wigner-Seitz radius, its core preference decreases, and thus this combination forms less segregated structures than what one would expect from the cohesive energy difference alone. Highly segregated structures (highly segregated core-shell or Janus-like) are expected to form when both the relative cohesive energy difference is greater than ∼20%, and the relative Wigner-Seitz radius difference is greater than ∼4%. Practical guides for predicting core-shell preference and degree of segregation level are presented.
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First Principles Study of Structure, Alloying and Electronic Properties of Mg-doped CuAg Nanoalloys. J CLUST SCI 2021. [DOI: 10.1007/s10876-020-01830-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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6
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Andreazza P, Lemoine A, Coati A, Nelli D, Ferrando R, Garreau Y, Creuze J, Andreazza-Vignolle C. From metastability to equilibrium during the sequential growth of Co-Ag supported clusters: a real-time investigation. NANOSCALE 2021; 13:6096-6104. [PMID: 33683240 DOI: 10.1039/d0nr08862e] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Atomic motions and morphological evolution of growing Co-Ag nanoparticles are followed in situ and in real time, by wide and small angle X-ray scattering obtained simultaneously in grazing incidence geometry (GISAXS and GIWAXS), in single or multi-wavelength anomalous modes. The structural analysis of the experimental data is performed with the aid of equilibrium Monte Carlo simulations and of molecular-dynamics simulations of nanoparticle growth. Growth is performed by depositing Co atoms above preformed Ag nanoparticles. This growth procedure is strongly out of equilibrium, because Ag tends to surface segregation, and generates complex growth sequences. The real time analysis of the growth allows to follow the nanoparticle evolution pathways almost atom-by-atom, determining the key mechanisms during Co deposition: starting with the incorporation of Co atoms in sub-surface positions, to the off-center Co domain formation, then by which the nanoparticles finally approach their equilibrium quasi-Janus then core-shell structures.
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Affiliation(s)
- P Andreazza
- Interfaces, Confinement, Matériaux et Nanostructures, ICMN, Université d'Orléans, CNRS, Orléans, France.
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7
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Fan X, Yahia L, Sacher E. Antimicrobial Properties of the Ag, Cu Nanoparticle System. BIOLOGY 2021; 10:137. [PMID: 33578705 PMCID: PMC7916421 DOI: 10.3390/biology10020137] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 02/03/2021] [Accepted: 02/07/2021] [Indexed: 12/11/2022]
Abstract
Microbes, including bacteria and fungi, easily form stable biofilms on many surfaces. Such biofilms have high resistance to antibiotics, and cause nosocomial and postoperative infections. The antimicrobial and antiviral behaviors of Ag and Cu nanoparticles (NPs) are well known, and possible mechanisms for their actions, such as released ions, reactive oxygen species (ROS), contact killing, the immunostimulatory effect, and others have been proposed. Ag and Cu NPs, and their derivative NPs, have different antimicrobial capacities and cytotoxicities. Factors, such as size, shape and surface treatment, influence their antimicrobial activities. The biomedical application of antimicrobial Ag and Cu NPs involves coating onto substrates, including textiles, polymers, ceramics, and metals. Because Ag and Cu are immiscible, synthetic AgCu nanoalloys have different microstructures, which impact their antimicrobial effects. When mixed, the combination of Ag and Cu NPs act synergistically, offering substantially enhanced antimicrobial behavior. However, when alloyed in Ag-Cu NPs, the antimicrobial behavior is even more enhanced. The reason for this enhancement is unclear. Here, we discuss these results and the possible behavior mechanisms that underlie them.
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Affiliation(s)
- Xinzhen Fan
- Laboratoire d’Innovation et d’Analyse de Bioperformance, Département de Génie Mécanique, Polytechnique Montréal, CP 6079, Succursale C-V, Montréal, QC H3C 3A7, Canada; (X.F.); (L.Y.)
| | - L’Hocine Yahia
- Laboratoire d’Innovation et d’Analyse de Bioperformance, Département de Génie Mécanique, Polytechnique Montréal, CP 6079, Succursale C-V, Montréal, QC H3C 3A7, Canada; (X.F.); (L.Y.)
| | - Edward Sacher
- Département de Génie Physique, Polytechnique Montréal, CP 6079, Succursale C-V, Montréal, QC H3C 3A7, Canada
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Bommireddy N, Palathedath SK. Templated bimetallic copper-silver nanostructures on pencil graphite for amperometric detection of nitrate for aquatic monitoring. J Electroanal Chem (Lausanne) 2020. [DOI: 10.1016/j.jelechem.2019.113660] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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9
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Nelli D, Ferrando R. Core-shell vs. multi-shell formation in nanoalloy evolution from disordered configurations. NANOSCALE 2019; 11:13040-13050. [PMID: 31265042 DOI: 10.1039/c9nr02963j] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The evolution towards equilibrium of AuCo, AgNi and AgCu nanoparticles is studied by molecular dynamics simulations. Nanoparticle sizes of about 2.5 nm are considered, in the temperature range from 300 to 700 K. The simulations reveal complex equilibration pathways, in which geometric structure and chemical ordering change with time. These nanoparticles present the same type of strong tendency to phase separation and to surface segregation of either Au or Ag, which lead to the same type of core@shell equilibrium structures. In spite of these similarities, the equilibration pathways of these nanoparticles from chemically disordered configurations present both quantitative and qualitative differences. Quantitative differences are found in the equilibration time scale, which is much longer in AgCu than in AgNi and AuCo. Qualitative differences are found in the presence or absence of geometric structure transformations, and in the formation of different types of three-shell metastable chemical ordering during evolution. It is also shown that surface segregation depends on the geometric structure, being faster in icosahedra than in fcc nanoparticles.
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Affiliation(s)
- Diana Nelli
- Physics Department, University of Genoa, via Dodecaneso 33, 16146 Genoa, Italy.
| | - Riccardo Ferrando
- Physics Department, University of Genoa, and CNR-IMEM, via Dodecaneso 33, 16146 Genoa, Italy.
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10
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Tchaplyguine M, Zhang C, Andersson T, Björneholm O. Ag-Cu oxide nanoparticles with high oxidation states: towards new high T c materials. Dalton Trans 2018; 47:16660-16667. [PMID: 30426128 DOI: 10.1039/c8dt04118k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In Ag-Cu oxides possible to fabricate so far, superconductivity has not been detected, but high conductivity was. In the quest for superconductivity the demand is to create a high and peculiar copper-oxygen coordination. Such coordination makes it non-trivial to determine Cu oxidation states, which may be several and co-existing. Another reason for uncertainty is in oxygen deficiency typical for superconducting crystals. Finally, Cu oxidation is influenced by the other metals in the substance. For chemical fabrication the difficulty is to tune the relative abundances of elements in a fine way. Ag-Cu oxides have been also produced by reactive co-sputtering of Cu and Ag, but the composition with high Cu oxidation states necessary for high conductivity has not been realized. In the present work we have fabricated Ag-Cu-oxide nanoparticles containing Cu and Ag in high oxidation states actual for superconductivity. The fabrication includes reactive sputtering of Ag and Cu metals, their vapour oxidation and aggregation into nanoparticles. The ability to create different and high oxidation states, also co-existing, is demonstrated. The fabrication approach also allows overcoming the poor miscibility of Cu and Ag. The nanoparticle composition and the oxidation states could be determined due to an experimental arrangement in which photoelectron spectroscopy is applied to free nanoparticles in a beam in vacuum, what allows avoiding any contact of the particles to a substrate or atmosphere. The combination of the fabrication and characterization methods has proven to be a powerful approach when fine composition tuning and control are desirable.
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11
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Liu X, Du J, Shao Y, Zhao SF, Yao KF. One-pot preparation of nanoporous Ag-Cu@Ag core-shell alloy with enhanced oxidative stability and robust antibacterial activity. Sci Rep 2017; 7:10249. [PMID: 28860477 PMCID: PMC5579282 DOI: 10.1038/s41598-017-10630-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 08/10/2017] [Indexed: 12/12/2022] Open
Abstract
Metallic core–shell nanostructures have inspired prominent research interests due to their better performances in catalytic, optical, electric, and magnetic applications as well as the less cost of noble metal than monometallic nanostructures, but limited by the complicated and expensive synthesis approaches. Development of one-pot and inexpensive method for metallic core–shell nanostructures’ synthesis is therefore of great significance. A novel Cu network supported nanoporous Ag-Cu alloy with an Ag shell and an Ag-Cu core was successfully synthesized by one-pot chemical dealloying of Zr-Cu-Ag-Al-O amorphous/crystalline composite, which provides a new way to prepare metallic core–shell nanostructures by a simple method. The prepared nanoporous Ag-Cu@Ag core-shell alloy demonstrates excellent air-stability at room temperature and enhanced oxidative stability even compared with other reported Cu@Ag core-shell micro-particles. In addition, the nanoporous Ag-Cu@Ag core-shell alloy also possesses robust antibacterial activity against E. Coli DH5α. The simple and low-cost synthesis method as well as the excellent oxidative stability promises the nanoporous Ag-Cu@Ag core-shell alloy potentially wide applications.
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Affiliation(s)
- Xue Liu
- School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, People's Republic of China.,Institute of Materials, China Academy of Engineering Physics, Mianyang, 621900, People's Republic of China
| | - Jing Du
- Institute of Biomechanics and Medical Engineering, School of Aerospace, Tsinghua University, Beijing, 100084, People's Republic of China
| | - Yang Shao
- School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, People's Republic of China
| | - Shao-Fan Zhao
- School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, People's Republic of China.,Qian Xuesen Laboratory of Space Technology, Beijing, 100094, People's Republic of China
| | - Ke-Fu Yao
- School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, People's Republic of China.
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12
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Solař P, Polonskyi O, Olbricht A, Hinz A, Shelemin A, Kylián O, Choukourov A, Faupel F, Biederman H. Single-step generation of metal-plasma polymer multicore@shell nanoparticles from the gas phase. Sci Rep 2017; 7:8514. [PMID: 28819149 PMCID: PMC5561131 DOI: 10.1038/s41598-017-08274-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 07/10/2017] [Indexed: 11/25/2022] Open
Abstract
Nanoparticles composed of multiple silver cores and a plasma polymer shell (multicore@shell) were prepared in a single step with a gas aggregation cluster source operating with Ar/hexamethyldisiloxane mixtures and optionally oxygen. The size distribution of the metal inclusions as well as the chemical composition and the thickness of the shells were found to be controlled by the composition of the working gas mixture. Shell matrices ranging from organosilicon plasma polymer to nearly stoichiometric SiO2 were obtained. The method allows facile fabrication of multicore@shell nanoparticles with tailored functional properties, as demonstrated here with the optical response.
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Affiliation(s)
- Pavel Solař
- Charles University, Faculty of Mathematics and Physics, Department of Macromolecular Physics, Prague, 182 00, Czech Republic.
| | - Oleksandr Polonskyi
- Kiel University, Faculty of Engineering, Chair for Multicomponent Materials, 24143, Kiel, Germany
| | - Ansgar Olbricht
- Kiel University, Faculty of Engineering, Chair for Multicomponent Materials, 24143, Kiel, Germany
| | - Alexander Hinz
- Kiel University, Faculty of Engineering, Chair for Multicomponent Materials, 24143, Kiel, Germany
| | - Artem Shelemin
- Charles University, Faculty of Mathematics and Physics, Department of Macromolecular Physics, Prague, 182 00, Czech Republic
| | - Ondřej Kylián
- Charles University, Faculty of Mathematics and Physics, Department of Macromolecular Physics, Prague, 182 00, Czech Republic
| | - Andrei Choukourov
- Charles University, Faculty of Mathematics and Physics, Department of Macromolecular Physics, Prague, 182 00, Czech Republic
| | - Franz Faupel
- Kiel University, Faculty of Engineering, Chair for Multicomponent Materials, 24143, Kiel, Germany
| | - Hynek Biederman
- Charles University, Faculty of Mathematics and Physics, Department of Macromolecular Physics, Prague, 182 00, Czech Republic
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Bochicchio D, Ferrando R, Panizon E, Rossi G. Structures and segregation patterns of Ag-Cu and Ag-Ni nanoalloys adsorbed on MgO(0 0 1). JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:064005. [PMID: 26795034 DOI: 10.1088/0953-8984/28/6/064005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Low-energy geometric structures and segregation patterns of Ag-Cu and Ag-Ni nanoparticles adsorbed on MgO(0 0 1) are searched for by global optimisation methods within an atomistic potential model. Sizes betwen 100 and 300 atoms are considered for several compositions. In all cases, Ag segregates to the nanoparticle surface, so that Cu@Ag and Ni@Ag core-shell arrangements are found, with off-centre cores for Ag-rich compositions. The behaviours of Ag-Cu and Ag-Ni differ at the interface with the MgO substrate. For Ag-Cu, some Cu atoms are at the interface even for compositions that are very rich in Ag, where Ag-Ni nanoparticles present an interface completely made of Ag atoms. Ag-Ni and Ag-Cu also differ concerning their geometric structures. With increasing Ag content, in Ag-Cu we find the structural sequence faulted fcc [Formula: see text] icosahedral [Formula: see text] fcc, while in Ag-Ni we find the sequence hcp [Formula: see text] faulted fcc-faulted hcp [Formula: see text] icosahedral [Formula: see text] fcc.
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Affiliation(s)
- Davide Bochicchio
- Dipartimento di Fisica dell'Università di Genova, Via Dodecaneso 33, 16146 Genoa, Italy
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15
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Jiang Z, Tian Y, Ding S, Wen J, Wang C. Facile synthesis of Cu–Ag hybrid nanowires with strong surface-enhanced Raman scattering sensitivity. CrystEngComm 2016. [DOI: 10.1039/c5ce02221e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The growth mechanism and regularity of Ag–Cu hybrid nanowires synthesized by a simple solution method have been analyzed.
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Affiliation(s)
- Zhi Jiang
- State Key Laboratory of Advanced Welding and Joining
- Harbin Institute of Technology
- Harbin, China
| | - Yanhong Tian
- State Key Laboratory of Advanced Welding and Joining
- Harbin Institute of Technology
- Harbin, China
| | - Su Ding
- State Key Laboratory of Advanced Welding and Joining
- Harbin Institute of Technology
- Harbin, China
| | - Jiayue Wen
- State Key Laboratory of Advanced Welding and Joining
- Harbin Institute of Technology
- Harbin, China
| | - Chenxi Wang
- State Key Laboratory of Advanced Welding and Joining
- Harbin Institute of Technology
- Harbin, China
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16
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Liquid-liquid phase separation of freely falling undercooled ternary Fe-Cu-Sn alloy. Sci Rep 2015; 5:16335. [PMID: 26552711 PMCID: PMC4639789 DOI: 10.1038/srep16335] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 10/14/2015] [Indexed: 11/13/2022] Open
Abstract
The active modulation and control of the liquid phase separation for high-temperature metallic systems are still challenging the development of advanced immiscible alloys. Here we present an attempt to manipulate the dynamic process of liquid-liquid phase separation for ternary Fe47.5Cu47.5Sn5 alloy. It was firstly dispersed into numerous droplets with 66 ~ 810 μm diameters and then highly undercooled and rapidly solidified under the containerless microgravity condition inside drop tube. 3-D phase field simulation was performed to explore the kinetic evolution of liquid phase separation. Through regulating the combined effects of undercooling level, phase separation time and Marangoni migration, three types of separation patterns were yielded: monotectic cell, core shell and dispersive structures. The two-layer core-shell morphology proved to be the most stable separation configuration owing to its lowest chemical potential. Whereas the monotectic cell and dispersive microstructures were both thermodynamically metastable transition states because of their highly active energy. The Sn solute partition profiles of Fe-rich core and Cu-rich shell in core-shell structures varied only slightly with cooling rate.
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17
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Ferrando R. Symmetry breaking and morphological instabilities in core-shell metallic nanoparticles. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:013003. [PMID: 25485754 DOI: 10.1088/0953-8984/27/1/013003] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Nanoalloys are bi- or multi-component metallic particles in the size range between 1 and 100 nm. Nanoalloys present a wide variety of structures and properties, which make them suitable for many applications in catalysis, optics, magnetism and biomedicine. This topical review is devoted to the structural properties of nanoalloys of weakly miscible metals, which are expected to present phase-separated arrangements of their components, such as core-shell and Janus arrangements. The focus is on singling out size- and composition-dependent transitions between these arrangements, showing that several transitions can be rationalized by a unifying concept, that is symmetry breaking, caused by the accumulation of strain at the atomic level and its subsequent release. The driving forces that rule the interplay between core-shell and other structures and determine the actual shapes of core and shell, and the placement of the core inside the shell are analyzed. Several systems, such as Ag-Cu, Ag-Co, Ag-Ni, Au-Co, Au-Pt, and Ir-Pt are treated, comparing computational results to experimental observations and simple analytical models. After treating the lowest-energy structures, which are representative of the equilibrium configurations at sufficiently low temperatures, high-temperature and growth kinetics effects are considered.
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Affiliation(s)
- Riccardo Ferrando
- Dipartimento di Fisica and CNR/IMEM, Università degli Studi di Genova, Via Dodecaneso 33, 16146, Genova, Italy
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18
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Liu X, Chen N, Gu JL, Du J, Yao KF. Novel Cu–Ag bimetallic porous nanomembrane prepared from a multi-component metallic glass. RSC Adv 2015. [DOI: 10.1039/c5ra08332j] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Cu–Ag bimetallic porous nanomembranes, prepared by chemical dealloying assisted with ultrasonic vibration, exhibit thicknesses of ∼5 to 50 nm, pore diameters of ∼10 to 20 nm and ligament feature sizes of ∼30 to 50 nm.
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Affiliation(s)
- Xue Liu
- Key Lab of Advanced Materials Processing Technology of Ministry of Education
- School of Materials Science and Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Na Chen
- Key Lab of Advanced Materials Processing Technology of Ministry of Education
- School of Materials Science and Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Jia-Lun Gu
- Key Lab of Advanced Materials Processing Technology of Ministry of Education
- School of Materials Science and Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Jing Du
- Institute of Biomechanics and Medical Engineering
- Department of Engineering Mechanics
- Tsinghua University
- Beijing 100084
- China
| | - Ke-Fu Yao
- Key Lab of Advanced Materials Processing Technology of Ministry of Education
- School of Materials Science and Engineering
- Tsinghua University
- Beijing 100084
- China
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Zhang C, Andersson T, Mikkelä MH, Mårsell E, Björneholm O, Xu X, Tchaplyguine M, Liu Z. Alloying and oxidation of in situ produced core-shell Al@Yb nanoalloy particles—An “on-the-fly” study. J Chem Phys 2014; 141:084302. [DOI: 10.1063/1.4893115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Datta S, Saha-Dasgupta T. Vegard's law-like behavior for Mn(m)Tc(n) alloy clusters: a first-principles prediction. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:185004. [PMID: 24728079 DOI: 10.1088/0953-8984/26/18/185004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
With a view to gaining an understanding of the alloying tendency of bimetallic nanoalloy clusters of isoelectronic constituents, we studied the structural and mixing behavior of MnmTcn alloy clusters with m + n = 13 for all possible compositions, using first-principles electronic structure calculations. Our study reports a favorable mixing tendency for the alloy clusters. The average bond lengths of the minimum energy structures show an overall linear variation with concentration, indicating a Vegard's law-like variation for the nanoalloy clusters, though the optimized structures undergo a structural transition from a closed and compact structure for the Mn-rich alloy clusters to an open layered-like structure for the Tc-rich alloy clusters. We work out a continuous and smooth interplay between hybridization and magnetization properties of the alloy clusters, which plays a vital role in the Vegard's law-like variation in their average bond lengths.
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Affiliation(s)
- S Datta
- Department of Condensed Matter Physics and Material Sciences, S N Bose National Centre for Basic Sciences, JD Block, Sector-III, Salt Lake City, Kolkata 700 098, India
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Tchaplyguine M, Zhang C, Andersson T, Björneholm O. Tuning the oxidation degree in sub-10 nm silver-oxide nanoparticles: From Ag2O monoxide to AgO (x> 1) superoxide. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2014.03.063] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Cottancin E, Langlois C, Lermé J, Broyer M, Lebeault MA, Pellarin M. Plasmon spectroscopy of small indium–silver clusters: monitoring the indium shell oxidation. Phys Chem Chem Phys 2014; 16:5763-73. [DOI: 10.1039/c3cp55135k] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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