Master Key to Coinage Metal Nanoclusters Treasure Chest: 38-metal Clusters

A nanocrystalline Co-Cr-Ni-Fe compositional complex alloy (CCA) film with a thickness of about 1 micron was produced by a multiple-beam-sputtering physical vapor deposition (PVD) technique. The main advantage of this novel method is that it does not require alloy targets, but rather uses commercially pure metal sources. Another benefit of the application of this technique is that it produces compositional gradient samples on a disk surface with a wide range of elemental concentrations, enabling combinatorial analysis of CCA films. In this study, the variation of the phase composition, the microstructure (crystallite size and defect density), and the mechanical performance (hardness and elastic modulus) as a function of the chemical composition was studied in a combinatorial Co-Cr-Ni-Fe thin film sample that was produced on a surface of a disk with a diameter of about 10 cm. The spatial variation of the crystallite size and the density of lattice defects (e.g., dislocations and twin faults) were investigated by X-ray diffraction line profile analysis performed on the patterns taken by synchrotron radiation. The hardness and the elastic modulus were measured by the nanoindentation technique. It was found that a single-phase face-centered cubic (fcc) structure was formed for a wide range of chemical compositions. The microstructure was nanocrystalline with a crystallite size of 10–27 nm and contained a high lattice defect density. The hardness and the elastic modulus values measured for very different compositions were in the ranges of 8.4–11.8 and 182–239 GPa, respectively.

Download Full-text

Quantifying electron-correlation effects in small coinage-metal clusters by ab initio calculations

Physical Chemistry Chemical Physics ◽

10.1039/d0cp06499h ◽

2021 ◽

Author(s):

Victor Giovanni de Pina ◽

Bráulio Gabriel Alencar Brito ◽

Guo -Q Hai ◽

Ladir Cândido

Keyword(s):

Monte Carlo ◽

Ab Initio Calculations ◽

Ab Initio ◽

Electron Correlation ◽

Metal Clusters ◽

Correlation Effects ◽

Diffusion Monte Carlo ◽

Coinage Metal ◽

Electron Correlation Effects ◽

Fixed Node

We investigate many-electron correlation effects in neutral and charged coinage-metal clusters Cun, Agn, and Aun (n = 1 − 4) by ab initio calculations using fixed-node diffusion Monte Carlo (FN-DMC)...

Download Full-text

The Interaction of Coinage Metal Clusters with the MgO(100) Surface

Journal of Chemical Theory and Computation ◽

10.1021/ct050073e ◽

2005 ◽

Vol 1 (5) ◽

pp. 972-985 ◽

Cited By ~ 102

Author(s):

Giovanni Barcaro ◽

Alessandro Fortunelli

Keyword(s):

Metal Clusters ◽

Coinage Metal

Download Full-text

Tool Wear Mechanisms during Machining of Alloy 625

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.275.204 ◽

2011 ◽

Vol 275 ◽

pp. 204-207 ◽

Cited By ~ 1

Author(s):

Lenka Fusova ◽

Pawel Rokicki ◽

Zdeněk Spotz ◽

Karel Saksl ◽

Carsten Siemers

Keyword(s):

Wear Mechanisms ◽

Gas Turbines ◽

Metal Cutting ◽

Elevated Temperatures ◽

Orthogonal Cutting ◽

Cutting Speed ◽

Production Costs ◽

Chemical Compositions ◽

Alloy 625 ◽

Wide Range

Nickel-base superalloys like Alloy 625 are widely used in power generation applications due to their unique properties especially at elevated temperatures. During the related component manufacturing for gas turbines up to 50% of the material has to be removed by metal cutting operations like milling, turning or drilling. As a result of high strength and toughness the machinability of Alloy 625 is generally poor and only low cutting speeds can be used. High-speed cutting of Alloy 625 on the other hand gets more important in industry to reduce manufacturing times and thus production costs. The cutting speed represents one of the most important factors that have influences on the tool life. The aim of this study is the analyses of wear mechanisms occurring during machining of Alloy 625. Orthogonal cutting experiments have been performed and different process parameters have been varied in a wide range. New and worn tools have been investigated by stereo microscopy, optical microscopy and scanning electron microscopy. Energy-dispersive X-ray analyses were used for the investigation of chemical compositions of the tool's surface as well as the nature of reaction products formed during the cutting process. Wear mechanisms observed in the machining experiments included abrasion, fracture and tribochemical effects. Specific wear features appeared depending on the mechanical and thermal conditions generated in the wear zones.

Download Full-text

Synthesis of cationically charged photoluminescent coinage metal nanoclusters by sputtering over a liquid polymer matrix

New Journal of Chemistry ◽

10.1039/c7nj01369h ◽

2017 ◽

Vol 41 (14) ◽

pp. 6828-6833 ◽

Cited By ~ 5

Author(s):

Ryan D. Corpuz ◽

Yohei Ishida ◽

Tetsu Yonezawa

Keyword(s):

Polymer Matrix ◽

Synthetic Approach ◽

Metal Nanoclusters ◽

Coinage Metal ◽

Biocompatible Polymer ◽

Liquid Polymer

A generic green synthetic approach to synthesize photoluminescent metal nanoclusters of known plasmonic elements via sputtering on a biocompatible polymer matrix.

Download Full-text

Graph Theory of Chemical Series and Broad Categorization of Clusters

International Journal of Chemistry ◽

10.5539/ijc.v10n1p17 ◽

2018 ◽

Vol 10 (1) ◽

pp. 17

Author(s):

Enos Masheija Rwantale Kiremire

Keyword(s):

Graph Theory ◽

Transition Metal ◽

Metal Clusters ◽

Transition Metal Clusters ◽

Recent Introduction ◽

Simple Concept ◽

Wide Range ◽

Nuclear Clusters

The recent introduction of skeletal numbers has made it much easier to analyze and categorize a wide range of many chemical clusters. In the process, it has been found that a large number of transition metal clusters with and without ligands are capped and do possess closo nuclear clusters. On the basis of the nuclear index, the clusters have been categorized into groups. The categorization of the clusters will greatly assist in promoting deeper understanding and the synthesis of novel clusters and their applications. A simple concept of graph theory of capping clusters has been introduced.

Download Full-text

The Nordre Strømfjord shear zone and the Arfersiorfik quartz diorite in Arfersiorfik, the Nagssugtoqidian orogen, West Greenland

Geological Survey of Denmark and Greenland Bulletin ◽

10.34194/geusb.v11.4922 ◽

2006 ◽

Vol 11 ◽

pp. 145-162 ◽

Cited By ~ 2

Author(s):

Kai Sørensen ◽

John A. Korstgård ◽

William E. Glassley ◽

Bo Møller Stensgaard

Keyword(s):

Shear Zone ◽

Volcanic Rocks ◽

Quartz Diorite ◽

Ductile Deformation ◽

Chemical Compositions ◽

West Greenland ◽

South West ◽

Wide Range ◽

Inland Ice ◽

Zone Deformation

The Nordre Strømfjord shear zone in the fjord Arfersiorfik, central West Greenland, consists of alternating panels of supracrustal rocks and orthogneisses which together form a vertical zone up to 7 km wide with sinistral transcurrent, ductile deformation, which occurred under middle amphibolite facies conditions. The pelitic and metavolcanic schists and paragneisses are all highly deformed, while the orthogneisses appear more variably deformed, with increasing deformation evident towards the supracrustal units. The c. 1.92 Ga Arfersiorfik quartz diorite is traceable for a distance of at least 35 km from the Inland Ice towards the west-south-west. Towards its northern contact with an intensely deformed schist unit it shows a similar pattern of increasing strain, which is accompanied by chemical and mineralogical changes. The metasomatic changes associated with the shear zone deformation are superimposed on a wide range of original chemical compositions, which reflect magmatic olivine and/ or pyroxene as well as hornblende fractionation trends. The chemistry of the Arfersiorfik quartz diorite suite as a whole is comparable to that of Phanerozoic plutonic and volcanic rocks of calc-alkaline affinity.

Download Full-text

Nucleation and Growth of Supported Metal Clusters at Defect Sites on Mgo and NaCl (001) Surfaces: The Cases of Pd and Ag

MRS Proceedings ◽

10.1557/proc-570-51 ◽

1999 ◽

Vol 570 ◽

Cited By ~ 5

Author(s):

J. A. Venables ◽

G. Haas ◽

H. Brune ◽

J.H. Harding

Keyword(s):

Deposition Temperature ◽

Metal Clusters ◽

Variable Temperature ◽

Nucleation And Growth ◽

Force Microscopy ◽

Atomic Force ◽

Defect Sites ◽

Wide Range ◽

Adsorption Surface

ABSTRACTNucleation and growth of metal clusters at defect sites is discussed in terms of rate equation models, which are applied to the cases of Pd and Ag on MgO(001) and NaCl(001) surfaces. Pd/MgO has been studied experimentally by variable temperature atomic force microscopy (AFM). The island density of Pd on Ar-cleaved surfaces was determined in-situ by AFM for a wide range of deposition temperature and flux, and stays constant over a remarkably wide range of parameters; for a particular flux, this plateau extends from 200 K ≤ T ≤ 600 K, but at higher temperatures the density decreases. The range of energies for defect trapping, adsorption, surface diffusion and pair binding are deduced, and compared with earlier data for Ag on NaCl, and with recent calculations for these metals on both NaCl and MgO

Download Full-text