Articles de revues : « Phase diagram of gold »

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Zhuang, Dian Xiang, Ming Xie, Lin Jing Liu, Man Men Liu, Yong Tai Chen, Ji Ming Zhang, You Cai Yang, Jie Qiong Hu, Sai Bei Wang et Song Wang. « Recent Research on Ternary Phase Diagram of Gold Alloy ». Advanced Materials Research 834-836 (octobre 2013) : 323–29. http://dx.doi.org/10.4028/www.scientific.net/amr.834-836.323.

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phase diagram is known as Maps of Materials Science. However, the existing precious metal phase diagrams are far from able to meet the needs of the development of the precious metal materials science and technology. In this paper, the recent research achievements of Au-Ag-Y ternary phase diagram by experimental method and Au-Pd-Zr ternary phase diagram by multi-phase equilibrium thermodynamic calculation software were introduced.

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Saccone, A., D. Macciò, S. Delfino et R. Ferro. « The neodymium-gold phase diagram ». Metallurgical and Materials Transactions A 30, n^o 5 (mai 1999) : 1169–76. http://dx.doi.org/10.1007/s11661-999-0266-7.

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Xiao-Jun, Liu, Moritomo Yutaka et Kojima Norimichi. « Electronic Phase Diagram of Mixed-Valence Gold Chloride ». Chinese Physics Letters 21, n^o 1 (janvier 2004) : 183–86. http://dx.doi.org/10.1088/0256-307x/21/1/055.

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Saccone, A., D. Macciò, S. Delfino et R. Ferro. « The phase diagram of the terbium–gold alloy system ». Intermetallics 8, n^o 3 (mars 2000) : 229–37. http://dx.doi.org/10.1016/s0966-9795(99)00099-0.

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Ryu, Seunghwa, et Wei Cai. « A gold–silicon potential fitted to the binary phase diagram ». Journal of Physics : Condensed Matter 22, n^o 5 (15 janvier 2010) : 055401. http://dx.doi.org/10.1088/0953-8984/22/5/055401.

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FAROOQ, M., et FARID A. KHWAJA. « MONTE CARLO CALCULATION OF ORDER-DISORDER PHASE DIAGRAM OF CU-AU ». International Journal of Modern Physics B 07, n^o 08 (avril 1993) : 1731–43. http://dx.doi.org/10.1142/s0217979293002547.

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The problem of order-disorder phase transition and phase diagram of the binary copper-gold alloy is analyzed using Monte-Carlo technique. Unlike traditional approaches, the interaction potentials used in our calculations are obtained from the experimental data of diffuse X-ray scattering for the system. The thermodynamic parameters such as configurational energy, specific heat and the order-disorder transition temperatures are calculated directly from the averages of these quantities over many different configurations after an initial equilbration period. The order-disorder phase diagram is constructed and compared with the experimental one, as well as with the results of some previous theoretical approaches.

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Löfgren, Joakim, Henrik Grönbeck, Kasper Moth-Poulsen et Paul Erhart. « Understanding the Phase Diagram of Self-Assembled Monolayers of Alkanethiolates on Gold ». Journal of Physical Chemistry C 120, n^o 22 (24 mai 2016) : 12059–67. http://dx.doi.org/10.1021/acs.jpcc.6b03283.

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Lu, S., N. Yao et I. A. Aksay. « Chemical Compostion Analysis on Sintered Gold and Platinum Nanoparticles ». Microscopy and Microanalysis 6, S2 (août 2000) : 28–29. http://dx.doi.org/10.1017/s1431927600032633.

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Nanoparticles continue to attract interests because they fall into intermediate stage between molecular and macroscopic materials. Due to their large surface-to-volume ratio, nanoparticles exhibit physical and chemical properties that differ markedly from those characterizing the bulk solid state. One example is the phase diagram of a nanomaterial. Because nanocrystals display clear changes in both the thermodynamics and the kinetics of phase transitions, we expect different solubility limits in the nanometer regime. This means that phases unstable or unobserved in extended solids may be prepared as nanocrystals. We synthesized Au and Pt nanoparticles and performed chemical analysis on the sintered agglomerates.The colloidal Au and Pt particles were synthesized according to Turkevich's method. An aqueous AuCl3 solution (50mg Au/L) was heated to 70°C. A determined amount of lwt% aqueous sodium citrate dihydrate (Na3C6H5O7.2H2O) solution was added such that the citrate-to-Au mass ratio was 10.

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Guisbiers, Grégory, Sergio Mejia-Rosales, Subarna Khanal, Francisco Ruiz-Zepeda, Robert L. Whetten et Miguel José-Yacaman. « Gold–Copper Nano-Alloy, “Tumbaga”, in the Era of Nano : Phase Diagram and Segregation ». Nano Letters 14, n^o 11 (27 octobre 2014) : 6718–26. http://dx.doi.org/10.1021/nl503584q.

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Wang, Yuanwei, Yu Tanabe et Hiromasa Yagyu. « Analysis of Synthesis Mechanism of Gold Nanoparticles Using Glass Microfluidics ». Proceedings 2, n^o 13 (3 décembre 2018) : 702. http://dx.doi.org/10.3390/proceedings2130702.

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According to LaMer diagram, a clearly separate of nucleation and grows step is required to synthesis of monodisperse nanoparticles. However, a critical mixing time Tc until the growth process is started, is not clear experimentally. In this paper, we prepared gold nanoparticles (GNPs) by liquid-phase reduction using citric acid on microfluidics with different flow rates. From relationship of the diameter of the prepared nanoparticle and the mixing time, Tc for the preparation of monodisperse GNPs was found for the first time.

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Hejazi, Sina, et Michael Fleischauer. « Understanding Lithium-Gold Electrochemical Reactions Using Operando X-Ray Diffraction ». ECS Meeting Abstracts MA2024-01, n^o 2 (9 août 2024) : 436. http://dx.doi.org/10.1149/ma2024-012436mtgabs.

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Gold electrodes are used in lithium-based battery research as catalysts and micro / quasi-reference electrodes despite their high cost and unclear reactivity with lithium. Here we present an investigation of the electrochemical reactions of gold-lithium (Au-Li) mixtures using variable-temperature electrochemistry and operando X-ray diffraction. Multiple solid solutions (alpha, beta, delta) and intermetallic phases (AuLi3, Au4Li15) are expected based on the equilibrium phase diagram.1 Previous electrochemical investigations conclusively identified only AuLi3;2,3 alpha and beta may be bypassed during lithium insertion, and the structure of delta is unclear.4 We are unaware of any previous reports of the electrochemical formation of Au4Li15. Metastable crystallographic solutions have been proposed.5 X-ray diffraction patterns collected during the galvanostatic lithiation of gold leaf (at 60 °C and a rate of ca. C/50) are provided in Figure 1. Reference diffraction patterns and the associated Powder Diffraction File card number are indicated, along with proposed phases.4,5 X-ray and electrochemical data align with earlier results suggesting that the equilibrium alpha and beta phases are seemingly bypassed during the first insertion. Delta is the first phase to form at a potential of 0.25 V vs. Li/Li+, followed by the formation of AuLi3 at 0.15 V vs. Li/Li+ at all conditions and Au4Li15 at 0.05 V vs. Li/Li+ in select conditions. Electrochemical data suggests AuLi3 may also have a small range of solubility. Peaks associated with AuLi3 and Au4Li15 align with existing literature but peaks associated with delta do not. Reactions are reversible to delta, followed by the formation of another phase near 0.3 V vs. Li/Li+ and alpha at potentials above 0.4 V vs. Li/Li+ during lithium removal. Significant hysteresis is present in cell potential and reaction pathways in the low-lithium content region. The second cycle (not shown) is reversible between alpha (not pure gold) and the terminal phase without a significant loss in capacity. Alternative crystallographic unit cell(s) for delta and other gold-lithium phases will be described. While the delta / AuLi3 reaction exhibited a consistent potential during lithium insertion and removal, the potential otherwise varied strongly with temperature, rate, and composition, implying that gold quasi-reference electrodes may not be suitable for lithium-ion battery research. References: A. D. Pelton, Bull. Alloy Phase Diagrams, 7, 228–231 (1986). A. N. Dey, J. Electrochem. Soc., 118, 1547 (1971). P. Bach, M. Stratmann, I. Valencia-Jaime, A. H. Romero, and F. U. Renner, Electrochim. Acta, 164, 81–89 (2015). A. J. Leenheer, K. L. Jungjohann, K. R. Zavadil, and C. T. Harris, ACS Nano, 10, 5670–5678 (2016). P. Bach, I. Valencia-Jaime, U. Rütt, O. Gutowski, A.H. Romero, and F.U. Renner, Chem. Mater., 28, 2941–2948 (2016). Figure 1. Galvanostatic and X-ray diffraction data collected during the first lithium insertion (alloying) and removal (de-alloying) cycle of a gold foil at 60 °C and a rate of C/50. X-ray intensity is shown on a logarithmic scale (provided). Peaks from X-ray powder diffraction cards and the associated card numbers are indicated. Figure 1

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Thipayarat, Kamolchanok, Ekasit Nisaratanaporn et Boonrat Lohwongwatana. « Investigation of Solid Solubility, Hardness, and Thermal Properties of Au-Ge-Sb System ». Advanced Materials Research 1016 (août 2014) : 336–41. http://dx.doi.org/10.4028/www.scientific.net/amr.1016.336.

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In recent years, the Au-Ge-Sb system has been studied as a possible alternative alloy for soldering applications [1-4]. The alloy has various fbenefits such as (i) low melting temperature which allows the alloy system to be used as a drop-in solution for high performance lead-free solders, (ii) three distinct phases of different hardness values (100, 150 and 500 HV) which offer the ability to fine tune the composition and microstructure to a wide range of properties, and (iii) limited solute solubility which offers ease of control and fine-tuning of microstructure, mechanical properties and colors. Gold compositions centered around 75wt% gold were modeled and selected using the CALPHAD (CALculation of PHAse Diagram) method. Predictions were later confirmed by experimental results. The alloy solidifies in the range of 242.5-261.7 °C. The overall hardness values were measured and confirmed to be within the volume average value of all the phases combined.

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Kadok, Joris, Marie-Cécile de Weerd, Pascal Boulet, Vincent Fournée et Julian Ledieu. « A new ternary compound with the BGa8Ir4 structure type in the Al–Au–Ir system ». Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 75, n^o 1 (23 janvier 2019) : 49–52. http://dx.doi.org/10.1107/s2052520618016712.

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Following the recent determination of the Al3AuIr structure, a new ternary phase has been identified in the Al–Au–Ir phase diagram. It has a chemical composition Al9(Au;Ir)4 with an apparently low gold content. Its crystal structure has been determined with single-crystal X-ray diffraction. The new compound crystallizes in the tetragonal crystal system and has been successfully solved in space group I41/acd (Pearson symbol tI104) with lattice parameters a = 8.6339 (2) and c = 21.8874 (7) Å. Atomic environments are described as well as similarities with the BGa8Ir4 compound.

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Salamakha, P., O. Sologub, O. Zaplatynsky, R. Ciach et J. Król. « Interaction of neodymium and silicon with gold : phase diagram and structural chemistry of ternary compounds ». Journal of Alloys and Compounds 264, n^o 1-2 (janvier 1998) : 197–200. http://dx.doi.org/10.1016/s0925-8388(97)00263-6.

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Durán-Meza, Ana L., Martha I. Escamilla-Ruiz, Xochitl F. Segovia-González, Maria V. Villagrana-Escareño, J. Roger Vega-Acosta et Jaime Ruiz-Garcia. « Encapsidation of Different Plasmonic Gold Nanoparticles by the CCMV CP ». Molecules 25, n^o 11 (5 juin 2020) : 2628. http://dx.doi.org/10.3390/molecules25112628.

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Different types of gold nanoparticles have been synthesized that show great potential in medical applications such as medical imaging, bio-analytical sensing and photothermal cancer therapy. However, their stability, polydispersity and biocompatibility are major issues of concern. For example, the synthesis of gold nanorods, obtained through the elongated micelle process, produce them with a high positive surface charge that is cytotoxic, while gold nanoshells are unstable and break down in a few weeks due to the Ostwald ripening process. In this work, we report the self-assembly of the capsid protein (CP) of cowpea chlorotic mottle virus (CCMV) around spherical gold nanoparticles, gold nanorods and gold nanoshells to form virus-like particles (VLPs). All gold nanoparticles were synthesized or treated to give them a negative surface charge, so they can interact with the positive N-terminus of the CP leading to the formation of the VLPs. To induce the protein self-assembly around the negative gold nanoparticles, we use different pH and ionic strength conditions determined from a CP phase diagram. The encapsidation with the viral CP will provide the nanoparticles better biocompatibility, stability, monodispersity and a new biological substrate on which can be introduced ligands toward specific cells, broadening the possibilities for medical applications.

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Liu, Zhong-Li, Ya-Ping Tao, Xiu-Lu Zhang et Ling-Cang Cai. « High-pressure phase diagram of gold from first-principles calculations : Converging to an isotropic atomic stacking order ». Computational Materials Science 114 (mars 2016) : 72–78. http://dx.doi.org/10.1016/j.commatsci.2015.12.009.

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Todorov, R., V. Katrova, T. Hristova-Vasileva et G. Milushev. « Structural and optical characterization of thin films from bimetallic Au-Sb system as tuneable plasmonic material for UV spectral range ». Journal of Physics : Conference Series 2436, n^o 1 (1 janvier 2023) : 012023. http://dx.doi.org/10.1088/1742-6596/2436/1/012023.

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Abstract The optical properties of silver and gold based bimetallic alloys make possible to adjust their plasma frequency. The direct alloying and plasmonic activity of thin layers from the Au-Sb system are presented in the present work. The thin films were deposited by thermal co-evaporation of gold and antinomy. The chemical and phase composition of thin films, were analysed by X-ray microanalysis and X-ray diffraction (XRD), respectively. The results of the X-ray microanalysis show that the composition of the thin layers corresponds well to the predetermined. The XRD patterns, depending on the envisaged compositions, show formation of intermetallic compound AuSb2 and binary alloys between the initial elements and the intermediate compound, which is in accordance with the Au-Sb phase diagram. The dispersion of the complex permittivity was determined by spectroscopic ellipsometry. The results show that the increase of the antimony content leads to an increase of the values of the imaginary part of the complex permittivity in the visible spectral region at photon energies greater than 3 eV, and a decrease in the ultraviolet spectral region. Based on the obtained dispersions of the complex permittivity, extinction cross-sections and local field enhancement of spherical Au-Sb nanoparticles were determined and their plasmon activity was evaluated.

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Ghasemi, Masoomeh, et Jonas Johansson. « Phase diagrams for understanding gold-seeded growth of GaAs and InAs nanowires ». Journal of Physics D : Applied Physics 50, n^o 13 (7 mars 2017) : 134002. http://dx.doi.org/10.1088/1361-6463/aa601c.

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Shou, Qinghui, Mitsuhiro Ebara, Jiaqi Wang, Qinggang Wang, Xiangfeng Liang, Huizhou Liu et Takao Aoyagi. « Preparation of phase diagram of gold nanorods in mixture solvent of DMSO and water and its application for efficient surface-modification ». Applied Surface Science 457 (novembre 2018) : 264–70. http://dx.doi.org/10.1016/j.apsusc.2018.06.261.

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Parfenov, Petr, Arkadiy Taranenko, Ilya Selyuzhenkov et Peter Senger. « Performance studies of anisotropic flow with MPD at NICA ». EPJ Web of Conferences 204 (2019) : 07010. http://dx.doi.org/10.1051/epjconf/201920407010.

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The Multi-Purpose Detector (MPD) at NICA collider has a substantial discovery potential concerning the exploration of the QCD phase diagram in the region of high net-baryon densities and moderate temperatures. The anisotropic transverse flow is one of the key observables to study the properties of dense matter created in heavy-ion collisions. The MPD performance for anisotropic flow measurements is studied with Monte-Carlo simulations of gold ions at NICA energies $\sqrt {{S_{NN}}} = 4 - 11\,{\rm{GeV}}$ using different heavy-ion event generators. Different combinations of the MPD detector subsystems are used to investigate the possible systematic biases in flow measurements, and to study effects of detector azimuthal non-uniformity. The resulting performance of the MPD for flow measurements is demonstrated for directed and elliptic flow of identified charged hadrons as a function of rapidity and transverse momentum in different centrality classes.

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Kojima, Norimichi. « Gold Valence Transition and Phase Diagram in the Mixed-Valence Complexes, M2[AuIX2][AuIIIX4] (M = Rb, Cs ; X = Cl, Br, and I) ». Bulletin of the Chemical Society of Japan 73, n^o 7 (juillet 2000) : 1445–60. http://dx.doi.org/10.1246/bcsj.73.1445.

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Hayes, F. H., W. T. Chao et J. A. J. Robinson. « Phase diagrams of (gold+binary solder) ternary alloy systems by smith thermal analysis ». Journal of Thermal Analysis 42, n^o 4 (octobre 1994) : 745–58. http://dx.doi.org/10.1007/bf02546747.

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Fiori, Giorgia, Andrada Pica, Salvatore Andrea Sciuto, Franco Marinozzi, Fabiano Bini et Andrea Scorza. « A Comparative Study on a Novel Quality Assessment Protocol Based on Image Analysis Methods for Color Doppler Ultrasound Diagnostic Systems ». Sensors 22, n^o 24 (15 décembre 2022) : 9868. http://dx.doi.org/10.3390/s22249868.

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Color Doppler (CD) imaging is widely used in diagnostics since it allows real-time detection and display of blood flow superimposed on the B-mode image. Nevertheless, to date, a shared worldwide standard on Doppler equipment testing is still lacking. In this context, the study herein proposed would give a contribution focusing on the combination of five test parameters to be included in a novel Quality Assessment (QA) protocol for CD systems testing. A first approach involving the use of the Kiviat diagram was investigated, assuming the diagram area, normalized with respect to one of the gold standards, as an index of the overall Doppler system performance. The QA parameters were obtained from the post-processing of CD data through the implementation of custom-written image analysis methods and procedures, here applied to three brand-new high-technology-level ultrasound systems. Experimental data were collected through phased and convex array probes, in two configuration settings, by means of a Doppler flow phantom set at different flow rate regimes. The outcomes confirmed that the Kiviat diagram might be a promising tool applied to quality controls of Doppler equipment, although further investigations should be performed to assess the sensitivity and specificity of the proposed approach.

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Golosov, Oleg, Ilya Selyuzhenkov et Evgeny Kashirin. « Data-Driven Methods for Spectator Symmetry Plane Estimation in CBM Experiment at FAIR ». Particles 4, n^o 3 (21 juillet 2021) : 354–60. http://dx.doi.org/10.3390/particles4030030.

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The Compressed Baryonic Matter experiment (CBM) at FAIR aims to study the area of the QCD phase diagram at high net baryon densities and moderate temperatures with collisions of heavy ions at sNN=2.8–4.9 GeV. The anisotropic transverse flow is one of the most important observable phenomena in a study of the properties of matter created in such collisions. Flow measurements require the knowledge of the collision symmetry plane, which can be determined from the deflection of the collision spectators in the plane transverse to the direction of the moving ions. The CBM performance for projectile spectator symmetry plane estimation is studied with GEANT4 Monte Carlo simulations using collisions of gold ions with beam momentum of 12A GeV/c generated with the DCM-QGSM-SMM model. Different data-driven methods to extract the correction factor in flow analysis for the resolution of the spectator symmetry plane estimated with the CBM Projectile Spectator Detector are investigated.

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Okrugin, Alexander, et Boris Gerasimov. « Formation of Intergrowths of Platinum-Group Minerals and Gold from Magmatogenic Ores in Relation to Phase Changes in Pt-Pd-Fe-Cu-Au System ». Minerals 14, n^o 3 (21 mars 2024) : 326. http://dx.doi.org/10.3390/min14030326.

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The article discusses the features of the chemical composition and the formation of intergrowths of platinum-group minerals, gold, gold-bearing phases, and other ore minerals present in placers collected from the Anabar River in the northeast part of the Siberian platform. Based on an analysis of changes in the phase compositions of these intergrowths of noble metals with other ore minerals on (Pt, Pd)-Fe-Au and Pd-Cu-Au phase equilibrium diagrams, potential trends in the crystallization of natural polymineral alloys from multicomponent low-sulfide metallic liquids are discussed. The similarity of the microstructures of natural and metallurgical alloys indicates that the formation of natural multiphase Au-PGE intergrowths occurred in a similar manner to the crystallization of multicomponent synthetic alloys. The authors suggest that magmatic Au-PGE mineralization occurs during the crystallization of a noble-metal-containing, low-sulfide, Cr-rich oxide melt separated from silicate mafic–ultramafic magma. Magmatic gold–platinum deposits are commonly associated with sulfide or oxide disseminated-schlieren ores in layered mafic–ultramafic intrusions. However, due to the high solubility of gold and platinoids in sulfide minerals, PGMs in sulfide ores occur as isomorphic impurities or as microphases and dispersed inclusions that cannot form placers. Therefore, the authors suggest that magmatic Au-PGE mineralization occurs during the crystallization of an immiscible low-sulfide, high-Cr oxide liquid separated from silicate mafic–ultramafic magma. In the northeast part of the Siberian platform, potential sources for these placers are likely alkaline, high-Ti mafic–ultramafic intrusions, as confirmed by the presence of silicate inclusions in ferroan platinum similar in composition to melteigite.

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Coropceanu, Igor, Eric M. Janke, Joshua Portner, Danny Haubold, Trung Dac Nguyen, Avishek Das, Christian P. N. Tanner et al. « Self-assembly of nanocrystals into strongly electronically coupled all-inorganic supercrystals ». Science 375, n^o 6587 (25 mars 2022) : 1422–26. http://dx.doi.org/10.1126/science.abm6753.

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Colloidal nanocrystals of metals, semiconductors, and other functional materials can self-assemble into long-range ordered crystalline and quasicrystalline phases, but insulating organic surface ligands prevent the development of collective electronic states in ordered nanocrystal assemblies. We reversibly self-assembled colloidal nanocrystals of gold, platinum, nickel, lead sulfide, and lead selenide with conductive inorganic ligands into supercrystals exhibiting optical and electronic properties consistent with strong electronic coupling between the constituent nanocrystals. The phase behavior of charge-stabilized nanocrystals can be rationalized and navigated with phase diagrams computed for particles interacting through short-range attractive potentials. By finely tuning interparticle interactions, the assembly was directed either through one-step nucleation or nonclassical two-step nucleation pathways. In the latter case, the nucleation was preceded by the formation of two metastable colloidal fluids.

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Dizer, Oleg A., Denis A. Rogozhnikov et Stanislav S. Naboichenko. « Thermodynamics of Copper Arsenious Raw Materials Dissolution in Nitric Acid ». Solid State Phenomena 316 (avril 2021) : 678–83. http://dx.doi.org/10.4028/www.scientific.net/ssp.316.678.

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This article describes thermodynamic study of hydrometallurgical method for processing of copper arsenious gold-containing raw material. Chemical and phase composition of the material were researched. Calculations of the Gibbs energy change were conducted for possible reactions of the main minerals, present in the raw material, with nitric acid. Eh-pH diagrams and solid/liquid equilibrium distribution diagrams, which were constructed in order to confirm the possibility of obtaining the required reaction products through nitric acid leaching of the studied raw material.

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Kojima, N., M. Hasegawa, H. Kitagawa, T. Kikegawa et O. Shimomura. « P-T Phase Diagram and Gold Valence State of the Perovskite-Type Mixed-Valence Compounds Cs2Au2X6 (X = Cl, Br, and I) under High Pressures ». Journal of the American Chemical Society 116, n^o 25 (décembre 1994) : 11368–74. http://dx.doi.org/10.1021/ja00104a016.

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Senger, Anna. « Simultaneous muon and reference hadron measurements in the compressed baryonic matter experiment at FAIR ». International Journal of Modern Physics E 29, n^o 02 (février 2020) : 2030003. http://dx.doi.org/10.1142/s0218301320300039.

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The mission of the Compressed Baryonic Matter (CBM) experiment at the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt is to explore the QCD phase diagram at high net baryon densities likely to exist in the core of neutron stars. The CBM detector system is designed to perform multi-differential measurements of hadrons and leptons in central gold-gold collisions at beam energies between 2 and 11 A GeV with unprecedented precision and statistics. In order to reduce the systematic errors of the lepton measurements, which generally suffer from a large combinatorial background, both electrons and muons will be measured with the same acceptance. Up to now, no di-muon measurements have been performed in heavy-ion collisions at beam energies below 158 A GeV. The main device for electron identification, a Ring Imaging Cherenkov (RICH) detector, can be replaced by a setup comprising hadron absorbers and tracking detectors for muon measurements. In order to obtain a complete picture of the reaction, it is important to measure simultaneously leptons and hadrons. This requirement is fulfilled for the RICH, which has a low material budget, and only little affects the trajectories of hadrons on their way to the Time-of-Flight (TOF) detector. In contrast, the simultaneous measurement of muons and hadrons within the same experimental acceptance poses a substantial challenge. This article reviews the simulated performance of the CBM experiment for muon identification, together with the possibility of simultaneous hadron measurements.

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GERBALDO, R., G. GHIGO, L. GOZZELINO, B. MINETTI, E. MEZZETTI, P. CARACINO, L. MARTINI, S. ZANNELLA, R. CHERUBINI et A. ROVELLI. « PHASE DIAGRAMS OF SURFACE HEAVY ION IRRADIATED BI-2223/AG TAPES ». International Journal of Modern Physics B 14, n^o 25n27 (30 octobre 2000) : 3153–58. http://dx.doi.org/10.1142/s0217979200003460.

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Surface columnar defects, SCDs, are produced in high quality (Bi,Pb) 2 Sr 2 Ca 2 Cu 3 O y / Ag tapes by irradiating them with 0.25 GeV gold ions only on a top layer up to ≈15% of the full volume. The ion beam is orthogonal to the tape plane. In this paper we report experimental results of the surface implantation of columnar defects both in the high-current and in the low-current regime with a particular emphasis on the influence of SCDs on the anisotropy dependent properties. Some characteristic labels of the SCD implantation are pointed out. A comparison between all the results in the two current regimes is made. A hint is given concerning analogous results obtained by means of transport electrical measurements. The experimental data can be interpreted by assuming that a new confined phase driven by SCDs sets up in both the current regimes. Acting on the dose, it is possible to obtain tunable control of the in-field performance in both regimes.

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Latsuzbaia, Roman, Emanuela Negro et Ger Koper. « Bicontinuous microemulsions for high yield, wet synthesis of ultrafine nanoparticles : a general approach ». Faraday Discussions 181 (2015) : 37–48. http://dx.doi.org/10.1039/c5fd00004a.

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The design of a synthesis strategy for metal nanoparticles by templating dense microemulsions is proposed. Particle size is controlled by surfactant size rather than by microemulsion composition. The strategy was demonstrated with various systems with different surfactant: cationic, anionic and non-ionic and of different sizes. Formulations were determined using the microemulsion phase diagrams. Synthesis was demonstrated for platinum nanoparticles with some examples for gold. The nanoparticles were subsequently extracted from the microemulsion by absorption onto a carbon support, after which the surfactant was recycled.

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Povar, Igor, Stefano Ubaldini, Oxana Spinu et Tudor Lupascu. « Thermodynamic analysis of the copper (I) homogeneous and heterogeneous speciation in ammonium thiosulfate leaching systems ». Canadian Journal of Chemistry 97, n^o 9 (septembre 2019) : 651–58. http://dx.doi.org/10.1139/cjc-2018-0446.

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The paper presents a new thermodynamic approach to studying mixed ligand complex formation reactions in the multi-component two-phase system “cuprous oxide-ammoniacal copper (I) thiosulfate aqueous solution” under real conditions. The quintessence of the developed approach consists in the thermodynamic analysis of concurrent reactions in the heterogeneous system Cu(I) – NH3 – S2O32− – H2O on the basis of the introduced notion of generalized reaction equations. A detailed thermodynamic analysis in ammonium thiosulfate leaching systems has considered the formation of mixed ligand complex species Cu(OH)i(NH3)j(S2O3)k. The new feature is to focus on the chemical description of the overall process of complex formation consisting of a series of concurrent reactions, where the nature and ratio of the concentrations of chemical species, formed in such reactions, depend on the ratio of the concentrations of the metal Cu+ and ligands, temperature, and other thermodynamic parameters. On the basis of the selected thermodynamic data for involved species, the thermodynamic stability areas of solid phase and the repartition of soluble and insoluble chemical species towards the solution pH and a number of total reagent concentrations in heterogeneous mixtures have been investigated. The diagrams of heterogeneous and homogeneous chemical equilibria are used for the graphical representation of complex equilibria and distribution of soluble and insoluble species in examined systems. The used approach utilizes thermodynamic relationships coupled with original mass balance constraints, where the solid phases are explicitly expressed. The obtained results are useful for optimization of the overall scheme of thiosulfate leaching in gold hydrometallurgy to minimize reagent consumption and maximize gold extraction.

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Jiang, Luyun, Wei Sun, Yajun Gao et Jianwei Zhao. « Geometric thermal phase diagrams for studying the thermal dynamic stability of hollow gold nanoballs at different temperatures ». Physical Chemistry Chemical Physics 16, n^o 14 (2014) : 6623. http://dx.doi.org/10.1039/c3cp54961e.

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Ghavami-Riabi, R., M. M. Seyedrahimi-Niaraq, R. Khalokakaie et M. R. Hazareh. « U-spatial statistic data modeled on a probability diagram for investigation of mineralization phases and exploration of shear zone gold deposits ». Journal of Geochemical Exploration 104, n^o 1-2 (janvier 2010) : 27–33. http://dx.doi.org/10.1016/j.gexplo.2009.10.002.

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Białobrzeska, Wioleta, Karolina Dziąbowska, Małgorzata Lisowska, M. Aiman Mohtar, Petr Muller, Borivoj Vojtesek, Radovan Krejcir et al. « An Ultrasensitive Biosensor for Detection of Femtogram Levels of the Cancer Antigen AGR2 Using Monoclonal Antibody Modified Screen-Printed Gold Electrodes ». Biosensors 11, n^o 6 (7 juin 2021) : 184. http://dx.doi.org/10.3390/bios11060184.

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The detection of cancer antigens is a major aim of cancer research in order to develop better patient management through early disease detection. Many cancers including prostate, lung, and ovarian secrete a protein disulfide isomerase protein named AGR2 that has been previously detected in urine and plasma using mass spectrometry. Here we determine whether a previously developed monoclonal antibody targeting AGR2 can be adapted from an indirect two-site ELISA format into a direct detector using solid-phase printed gold electrodes. The screen-printed gold electrode was surface functionalized with the anti-AGR2 specific monoclonal antibody. The interaction of the recombinant AGR2 protein and the anti-AGR2 monoclonal antibody functionalized electrode changed its electrochemical impedance spectra. Nyquist diagrams were obtained after incubation in an increasing concentration of purified AGR2 protein with a range of concentrations from 0.01 fg/mL to 10 fg/mL. In addition, detection of the AGR2 antigen can be achieved from cell lysates in medium or artificial buffer. These data highlight the utility of an AGR2-specific monoclonal antibody that can be functionalized onto a gold printed electrode for a one-step capture and quantitation of the target antigen. These platforms have the potential for supporting methodologies using more complex bodily fluids including plasma and urine for improved cancer diagnostics.

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Zang, Weisheng, William S. Fyfe et Robert L. Barnett. « A silver-palladium alloy from the Bahia lateritic gold deposit, Carajas, Brazil ». Mineralogical Magazine 56, n^o 382 (mars 1992) : 47–51. http://dx.doi.org/10.1180/minmag.1992.056.382.06.

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AbstractA silver-palladium alloy with structural formula close to AgPd has been found in laterite from the Bahia lateritic gold deposit. The alloy occurs in a void of an iron oxide nodule, associated with goethite and hematite. The angular shape and protuberances of the alloy grains suggest crystal growth in a lateritic environment, indicating that the alloy is a secondary mineral precipitated during lateritisation. The oxidation of sulphides of the parent rocks probably favoured the migration of palladium and silver as transient thiosulphate and sulphite complexes. Destruction of the thiosulphate and sulphite ligands could result in precipitation of both palladium and silver as an alloy. Eh-pH phase diagrams for Pd-H2O-C1 and Ag-H2O-C1 systems show that both palladium and silver are stable in lateritic environments under lower redox potentials. Such an environment may exist at the top of the ferruginous zone due to the abundant organic matter near the surface.

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Artemiev, Dmitry, Robert Krymsky, Boris Belyatsky et Dmitry Ashikhmin. « The age of mineralization of Mayskoe gold ore deposit (Central Chukotka) : results of Re-Os isotopic dating ». Journal of Mining Institute 243 (10 juin 2020) : 266. http://dx.doi.org/10.31897/pmi.2020.3.266.

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The article presents the results of the sulfide mineralization dating of the Mayskoe gold ore deposit using the Re-Os isotope system and isochron age estimation method of the main sulfide minerals: arsenopyrite, pyrite, and antimonite. The complex multistage formation of the studied sulfides, as well as the close intergrowths of genetically different mineral phases, did not allow obtaining a single rhenium-osmium isochron corresponding to the formation time of sulfide mineralization. Isochrones for single minerals, collected from each sulfide sample, turned out to be the result of isotopically distinct components mixture (radiogenic crustal and non-radiogenic mantle) and do not make sense from the geochronological point of view. In terms of geology, the most significant result of the study is an age estimation of 128.8 ± 4.4 Ma, obtained for the sulfide mineralization of Mayskoe deposit using Re-Os isotope dating of single fractions of pyrite and antimonite of the ore mineralization stage. While arsenopyrite is most closely associated with gold mineralization, one of the arsenopyrite varieties corrodes framboidal pyrite of the pre-ore stage, has a maximum of the crust component in the osmium isotopic composition and forms a mixing line in the isochron diagram with an apparent formation age of 458 ± 18 Ma. The initial osmium isotopic composition of the studied sulfides indicates a mixed mantle-crust source of sulfide mineralization. The issue of simultaneous ore genesis and granitoid magmatism in the Mayskoe deposit remained unresolved (the age of granitoids according to the U-Pb zircon system is 108 Ma). However, a possible solution could be the further determination of the Re-Os isochron age of the ore mineralization sulphides from the single paragenesis of a specific sample containing both arsenopyrite and pyrite (+ antimonite) with gold.

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Umar, U. S. « METAMORPHISM AND DEFORMATION OF GOLD-BEARING NEOPROTEROZOIC WONAKA SCHIST BELT, NORTHWEST-NIGERIA. » Open Journal of Physical Science (ISSN : 2734-2123) 5, n^o 1 (10 juillet 2024) : 1–17. http://dx.doi.org/10.52417/ojps.v5i1.626.

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The role of metamorphism and deformation is indispensable in the occurrences of gold mineralization worldwide. In this work, deformation and metamorphic conditions for gold-bearing Neoproterozoic Wonaka Schist Belt; located around Kutcheri town of Tsafe Local Government of Zamfara State, was investigated. This is achieved using metamorphic litho-minerals obtained from ternary plots via X-Ray fluorescence (XRF) geochemical data, and directly using minerals phases from X-Ray Diffraction (XRD) technique. Index minerals identified from petrographic analysis previously suggest low to medium-grade metamorphism (M1). XRD analysis indicates quartz, albite, oligoclase, microcline, chlorite, and biotite, suggesting greenschist to lower amphibolite facies (M2). Sillimanite, andalusite, kyanite, staurolite, chlorite, biotite, and garnet were identified from the ternary plots using XRF major oxides, indicating upper amphibolite to granulite facies metamorphism (M3). This is typical of prograde metamorphism, granulite facie metamorphic grade is indicated. Na2O/Al2O3 versus K2O/Al2O3 for petrogenetic character suggests shale provenance, while the trace elements spider diagram indicates Wonaka litho-units as co-genetic compositionally, as high concentrations of V and Cr linked the petrogenetic affinity to mafic sources. Three circles of deformations are indicated; ductile deformation (D1) of the paleosome Schist producing foliations and lineation, brittle type (D2) in mid Pan-African and was accompanied by several fractures and felsic intrusions. Late Pan-African (D3) involves the folding of banded orthogneisses, the development of boudinage as well as intense shearing (ductile fault). Geospatial analysis of the fractures suggests that they represent regional Pan-African sutures cross-cutting Nigeria into the Atlantic and up to South American plate. The research therefore concludes that Au-fluid emanating through this regional event, utilizes D2 as channel ways and loci. D3 with M3 engulfed the entire structures repositioning the geometry to its present disposition.

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KOZHONOV, Almaz, Valentin CHANTURIA, Kulgamal NOGAEVA et Yessil ALPIEV. « Technological basis of processing skarn copper-gold-bearing ores of the Kyrgyz Republic ». Sustainable Development of Mountain Territories 15, n^o 3 (30 septembre 2023) : 693–706. http://dx.doi.org/10.21177/1998-4502-2023-15-3-693-706.

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Introduction. The paper studies the matters of processing of skarn copper-gold ores from a deposit in the Kyrgyz Republic. Materials and methods. As a study task, the authors performed an analysis of the material composition, including micro- and macroscopic types of analyses are presented. Results. Textural-structural analysis and mineralogical characteristics of the main ore minerals is detailed. The characteristic features of the material composition of the studied types of ores are highlighted and described. The reagent suite for processing of skarn ores has been established by means of additional feed of weakly selective depressants (Na2SiO3) and effective flotation reagents to the process, the introduction of which can significantly improve the concentrate quality. The study direction is also supplemented by the consideration and introduction of the process of mechanical activation into the process flow diagram as a reserve in increasing the grade of metals in the concentrate through the mechanical liberation of minerals by ultrafine grinding. The forms of metal loss with concentrating tailings, which are represented by wollastonite, garnet (andradite) and pyroxenes, clay-micaceous minerals, feldspars, and talc are determined. Discussion. The main losses of sulphide copper are associated with the presence of intergrowths of copper minerals with barren minerals in the samples. When evaluating copper minerals in tailings, copper is present in sulphide minerals – 79.2% and 20.8% rel. belongs to the oxide minerals. Conclusion. The paper summarizes the results of the study with the developed closed flotation flowsheet for the processing of copper-gold skarn ores, which makes it possible to obtain the flotation concentrate with grade of Cu – 25.01%, Au – 55.02g/t, Ag – 401g/t, with recovery into concentrate of Cu – 84.65%, Au – 87.94%, Ag – 89.44%. Concentrate output 2.33%. The implementation of the proposed flowsheet will ensure the achievement of planned production performance in the processing of skarn ores. Resume. At the end of the study work, the authors issued recommendations on adjusting the reagent suite with the inclusion of the weakly selective depressant – liquid glass (Na2SiO3), introducing the process of attritioning the feed of the cleaning operation (ultrafine regrinding) and considering the regularity of the phase composition of the copper minerals of skarn ore from the copper grade, providing the initial grade of copper at 0.9-1.0% in the processed ore by blending the ore feed ore to the concentrator. Suggestions for practical application and direction for future research. The materials of the paper can be useful for mining and processing enterprises when processing skarn copper-gold ores.

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Abshari, Fatemeh, Salih Veziroglu, Alexander Vahl et Martina Gerken. « Mimicking Axons by Conductive Metal Lines Formed by Photocatalytically Grown Gold ». ECS Meeting Abstracts MA2024-01, n^o 57 (9 août 2024) : 3000. http://dx.doi.org/10.1149/ma2024-01573000mtgabs.

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Nanoionic memristive devices based on the field−driven migration of metal cations and oxygen vacancies have gathered high interest in the scientific community for their capability to technically mimic synaptic connections. Less attention has been given to long−range global plasticity in artificial neuronal networks. The aim of our research is to use light−stimulated growth of gold metal lines to technically mimic the growth of long−range axonal connections for neuromorphic computing architectures. For this purpose, we investigate the formation of metal lines by UV−light−stimulus−driven photocatalytic deposition of gold on titanium dioxide layers. In this study, we present a significant contribution that stems from our active involvement in CRC 1461- Neurotronics, a pivotal initiative funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation). Our research falls under Project-ID 434434223 – SFB 1461, within the broader context of Bio-inspired information pathways. 0.8-mm wide photoactive titanium dioxide lines are defined by photolithography on a Sodalime glass substrate. We deposited a 70 nm thick titanium dioxide line on a 10 nm thick indium tin oxide adhesion layer by DC sputtering. The substrate was then heat treated for 90 minutes at 400°C and subsequently cooled on a metal plate to achieve the photocatalytically active anatase phase of titanium dioxide [1]. The growth process is conducted in a beaker by reduction from an aqueous gold chloride precursor solution (HAuCl4). In each step of the growth process, the substrate is placed in a beaker containing 15 ml of the precursor. The solution is obtained by dissolving 15 mg of HAuCl4 powder in 60 ml of deionized water. We utilize a UV LED with the peak wavelength of 365 nm and an approximate intensity of 1.8 - 2.7 mW/cm² to illuminate the sample in the beaker. The illumination time and UV intensity are crucial for this dynamic process. Here, we illuminated the sample for 12 hours and refreshed the solution every 2 hours. After each refreshment of the solution, the substrate is washed thoroughly with deionized (DI) water and is dried under nitrogen gas. We analyze the surface properties of grown gold utilizing scanning electron microscopy (SEM) and measure the conductance of the grown lines by applying voltage via the needles of a hard contact probe station. In the first experiments the growth of gold clusters on the surface is observed instead of the homogeneous gold coverage of the photolithographically defined titanium dioxide lines, which are needed for long-range electrical connections. Then, we coincidentally observed that the presence of a scratch on the titanium dioxide line led to the growth of continuous gold lines on the damaged area. Subsequently, deliberate scratches were introduced manually using tweezers, varying in both size and thickness. SEM images depict islands and covered areas, with notable growth observed on the scratched regions. Remarkably, wider scratches exhibit a proportionally increased width of the grown lines, and a uniform line devoid of any gaps is distinctly visible on broader scratches. We observed particle growth on thinner lines. However, unlike the uniform alignment observed in wider scratches, these particles did not coalesce into a continuous line. Instead, they remained separated from each other, exhibiting small gaps between individual particles. The morphological analysis of the grown gold line using SEM reveals a crystalline morphology of particles. As the primary objective of this research is to mimic axons with gold lines, ensuring conductivity is crucial for obtaining long−range electrical connections mimicking axons. To achieve this, voltage was applied using the needles of a hard contact probe station, and the resulting current was measured. The linear behavior observed in the I–V diagram of the wider line serves as a confirmation of its conductance (≈0.003 S). References: [1] Veziroglu, S., Paulsen, M., Schardt, J., Adejube, B., Aktas, C., Vahl, A., & Gerken, M. (2023). Photocatalytic Deposition for Metal Line Formation. In Bio-Inspired Information Pathways: From Neuroscience to Neurotronics (pp. 241-263). Cham: Springer International Publishing. Figure 1

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Mathieu, Lucie, Taylor D. Wasuita, Ross Sherlock, Fred Speidel, Jeffrey H. Marsh, Benoît Dubé et Olivier Côté-Mantha. « Zircon from Altered Monzonite Rocks Provides Insights into Magmatic and Mineralizing Processes at the Douay Au Project, Abitibi Greenstone Belt ». Geosciences 12, n^o 3 (2 mars 2022) : 114. http://dx.doi.org/10.3390/geosciences12030114.

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Zircon provides essential information on the age and oxidation state of magmatic systems and can be used to characterize magmatic-hydrothermal Au mineralizing systems. Using the Douay intrusion-related gold system (IRGS) as a type example of Neoarchean syenite-associated mineralization (Abitibi greenstone belt), we demonstrate that zircon from altered quartz-monzonite rocks can also be used to infer the age of a magmatic-hydrothermal event. Here, zircon chemistry is used to identify the following sequence of events at the Douay exploration project: (1) the crystallization of zircon at ~2690 Ma in evolved residual melts with distinct U-contents (quartz-monzonite magma); (2) the extensive radiation damage for the U-rich grains over a period of ~10–15 My; and (3) the alteration of zircon grains at ~2676 Ma by interaction with magmatic-hydrothermal mineralizing fluids derived from syenite and carbonatite intrusive phases. This study also distinguishes extensively altered zircon grains from pristine to least-altered zircon formed in distinct magmatic environments using a Th/U vs. U discrimination diagram.

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Jiang, Wenfeng, Zhi-bei Qu, Prashant Kumar, Drew Vecchio, Yuefei Wang, Yu Ma, Joong Hwan Bahng et al. « Emergence of complexity in hierarchically organized chiral particles ». Science 368, n^o 6491 (9 avril 2020) : 642–48. http://dx.doi.org/10.1126/science.aaz7949.

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The structural complexity of composite biomaterials and biomineralized particles arises from the hierarchical ordering of inorganic building blocks over multiple scales. Although empirical observations of complex nanoassemblies are abundant, the physicochemical mechanisms leading to their geometrical complexity are still puzzling, especially for nonuniformly sized components. We report the self-assembly of hierarchically organized particles (HOPs) from polydisperse gold thiolate nanoplatelets with cysteine surface ligands. Graph theory methods indicate that these HOPs, which feature twisted spikes and other morphologies, display higher complexity than their biological counterparts. Their intricate organization emerges from competing chirality-dependent assembly restrictions that render assembly pathways primarily dependent on nanoparticle symmetry rather than size. These findings and HOP phase diagrams open a pathway to a large family of colloids with complex architectures and unusual chiroptical and chemical properties.

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Hejazi, Sina, et Michael Fleischauer. « Optimizing Operando Electrochemical and X-Ray Diffraction Parameters for High-Resolution Measurements of Lithium-Based Battery Materials ». ECS Meeting Abstracts MA2024-01, n^o 46 (9 août 2024) : 2592. http://dx.doi.org/10.1149/ma2024-01462592mtgabs.

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Advances in lithium-based batteries depend on understanding the mechanisms behind electrode performance. Operando methods are very powerful and useful for decoupling thermodynamic and kinetic (e.g. diffusion) limitations, but impose challenges with data collection and analysis. Electrode composition changes as lithium is inserted or removed (according to the electrochemical conditions); composition resolution is defined by the current, (temperature-dependent) diffusion rate within the electrode, and the time to collect a diffraction pattern. Many material systems of interest require less than 1 atomic percent composition resolution to verify (or question) the expected crystalline phases, and separate composition gradients imposed by slow diffusion from the presence of solid solutions. Solid-solution ranges can be particularly challenging as the cell potential may change quickly over a very small composition range. Some advanced techniques use machine learning to optimize pattern collection time by comparing the measured diffraction pattern with references, and focusing on specific scattering angles to identify materials.1 Although powerful, this method is not well suited for materials with metastable or unidentified phases, e.g. metal alloys for advanced lithium-based batteries. Here we will describe a robust and low-cost platform for operando electrochemical and crystallographic measurements of lithium-based electrode materials. Electrode composition can be monitored at low to moderate rate electrochemical conditions using laboratory diffractometers and at high rates using some synchrotron-based diffractometers. Our test cell is based on Conflat-style vaccum flanges and a beryllium window;2 this design enables all standard two electrode electrochemical tests on e.g. lithium-based negative electrode materials with hermetic sealing and controlled pressure. Results from the electrochemical lithiation and delithiation of gold will be presented as a case study. Operando studies of lithium-gold reactivity are of interest since many lithium-gold phases have poorly defined unit cells and solid solution ranges,3 and gold electrodes are a common choice for in-situ / operando measurements in electron microscopes. A wide range of scattering angle is required to collect a sufficient number of peaks for unit cell indexing, which necessarily increases collection time and impacts composition resolution. We will discuss the influence of detector type and scan time (collection plus movement) on composition resolution as a function of electrochemical conditions (current, potential range, and temperature). Results from point, 1D, and 2D detectors on laboratory and synchrotron diffractometers will be provided, along with general strategies to optimize method resolution. References: Szmanski, N.J. et al., Nature Computational Materials, 9, 31 (2023). Sendetskyi, O. et al, J. Applied Crystallography, 54, 1416 (2021). A. D. Pelton, Bull. Alloy Phase Diagrams, 7, 228–231 (1986). Figure 1. Operando electrochemical X-ray diffraction heat maps before (a) and after (b) adjustment of operational and XRD data collection parameters. Figure 1

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Fallahzadeh, Rasoul, Fabio Bozzoli, Luca Cattani, Luca Pagliarini, Niloofar Naeimabadi et Muhammad Waheed Azam. « A Molecular Dynamics Perspective on the Impacts of Random Rough Surface, Film Thickness, and Substrate Temperature on the Adsorbed Film’s Liquid–Vapor Phase Transition Regime ». Sci 6, n^o 2 (3 juin 2024) : 33. http://dx.doi.org/10.3390/sci6020033.

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While recent studies have proven an unexpected liquid–vapor phase transition of adsorbed liquid films, a comprehensive description of the mechanisms of different types of phase change regimes over realistic representations of random rough surfaces is absent in the literature. The current comprehensive study investigates the effects of a gold random rough surface, liquid film thickness, and substrate temperature on the liquid–vapor phase change regime of an adsorbed sodium liquid film, considering the evaporator section of a wicked heat pipe (WHP) using a molecular dynamics (MD) simulation. At first, to generate a realistic random rough surface, a new and promising method is proposed that is entirely based on MD simulations. Then, to simulate the evaporator section of a WHP, a unique configuration for eliminating the vapor domain is developed. The simulation results reveal that three distinct regimes, namely, normal evaporation, cluster boiling, and film boiling, could be identified, which are presented on two-dimensional diagrams with the substrate temperature and liquid film thickness as coordinates for the ideally smooth and random rough surfaces. The results also manifest that even though using the random rough surface could lead to different phase transition regimes, the type of regime depends mainly on the substrate temperature and liquid film thickness. Furthermore, this study displays two different modes for normal evaporation. Also, it is shown that the impacts of the liquid film thickness and substrate temperature on the mode of normal evaporation are much more significant than the surface roughness.

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Murzin, V. V., К. N. Malitch, I. Yu Badanina, D. A. Varlamov et I. S. Chashchukhin. « Mineral assemblages from chromitites of the Alapaevsk dunite-harzburgite massif (Middle Urals) ». LITHOSPHERE (Russia) 23, n^o 5 (3 novembre 2023) : 740–65. http://dx.doi.org/10.24930/1681-9004-2023-23-5-740-765.

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Research subject. Minerals and mineral assemblages of noble elements in chromitites of the Alapaevsk massif. Aim. A systematic mineralogical study of high-chromium (Cr) and alumina-rich (Al) chromitites with the development of a sequence scheme for mineral formation, including platinum-group minerals (PGMs) and gold alloys. Materials and Methods. Samples of high-Cr and Al chromitites from chromite deposits in various parts of the Alapaevsk massif. Scanning electron microscopy (Tescan VEGAII XMU and JSM-6390LV Jeol with EDX INCA Energy 450 X-Max 80 spectrometers) and electron microprobe analysis (Cameca SX 100 with five wave spectrometers) were used. Results. A diagram showing the sequence of mineral formation in chromitites was designed; primary and secondary mineral assemblages were distinguished, with the latter assemblage being divided into early and late mineral associations. Primary assemblages of high-Cr (Cr2O3 > 50 wt %) and Al (Cr2O3 < 50 wt %) ores are represented by similar minerals, including chromespinel, clinopyroxene, and olivine, with characteristically distinct compositions of these minerals in each type of ores. Minerals of the primary assemblage are synchronous with chrome-spinel and are represented by pentlandite, Cu-bearing pentlandite, chalcopyrite, pyrrhotite, bornite, as well as PGMs (laurite RuS2, erlichmanite OsS2, native osmium) and Cu-rich gold. Minerals of the secondary early association occur in the form of polyphase inclusions within chrome-spinel. Polyphase inclusions are composed of Cr-bearing chlorite, amphibole, garnet, sulfides (millerite, heazlewoodite) and minerals of native elements, including (Ni, Cr)-bearing copper, nickel-bearing copper, (Cu, Fe, Cr)-bearing nickel, awaruite. Noble metal minerals from the secondary early association were found only in Al chromitites and are represented by laurite, Pt- and Pd arsenides and stibnides, Ru-bearing pentlandite, and high-grade native gold. The secondary late mineral association consists of native copper and awaruite, which are intergrown with serpentine in high-Cr ore. The temperature conditions for the formation of secondary assemblages were estimated using a chlorite geothermometer. The formation temperatures of the studied chlorites from chromitites fall within the range of 250–284°C. Conclusions. Noble metal minerals from secondary associations were formed at temperatures below 350°C together with garnet, amphibole, chlorite, and nickel sulfides. Grains of primary Os–Ir–Ru alloys during epigenetic processes underwent sulfurization with the formation of a fine-grained porous mixture of native and sulfide (sometimes with As) phases, and replacement by Ru-pentlandite. The presence of awaruite and native Cu and Ni in both primary and secondary assemblages of chromotites indicates the reducing conditions for the formation of noble metal minerals. The limited occurrence of high-Cr ores, along with the manifested processes of sulfurization for primary grains of Os–Ir–Ru alloys, led to the scarcity of detrital PGM in the area of the Alapaevsk massif.

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Roberson, Ed. « Phase Diagram ». Callaloo 29, n^o 1 (2006) : 20. http://dx.doi.org/10.1353/cal.2006.0067.

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KHAN, ABDUL FAHEEM, et A. S. M. A. HASEEB. « STUDY OF Co/Sn MULTILAYER SYSTEM WITH VARIOUS TIN LAYER THICKNESS AND REFLOW TEMPERATURES ». Surface Review and Letters 26, n^o 03 (24 mars 2019) : 1850153. http://dx.doi.org/10.1142/s0218625x18501536.

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Co–Sn–Co multi-layer films with various Sn-layer thicknesses have been deposited by using the electrodeposition technique. The deposition was performed at room temperature on gold coated silicon substrates. The thickness of Sn layer was kept [Formula: see text]4.5, 2.5, 1.5 and 1[Formula: see text][Formula: see text]m, while the thickness of each Co layer was fixed to [Formula: see text]0.75[Formula: see text][Formula: see text]m. The Sn layer was sandwiched between two Co layers. The total thickness of the films was [Formula: see text]6, 4, 3, 2.5[Formula: see text][Formula: see text]m, respectively. The intended ratio of Sn was about 25 at.% while Co was about 75 at.%. The separation inside the Sn-layer has been observed at higher Sn-layer thicknesses with increasing reflow temperature. It may be due to the combined effect of thermal stress arising during cooling from elevated reflow temperatures and solidification shrinkage in the thick Sn layer due to the formation of IMC CoSn2. However, 1[Formula: see text][Formula: see text]m has been found to be a critical thickness, which remains intact when sandwiched between two cobalt layers. The structure of these multi-layer films was studied as a function of temperature. It has been observed from X-ray diffraction (XRD) that the as-deposited films exhibit strong peaks belonging to elemental Co and Sn. At temperatures of 270–290∘C, CoSn2 begins to appear and grow at the interfaces and in the middle of Sn layer with the decrease in elemental Sn. However, sufficient amount of Co is still present in pure form as is evident by the XRD and field emission scanning electron microscopy images at all temperatures. This study confirms that only one reaction product, viz. CoSn2, formed in as-deposited during reflow at temperatures 270–290∘C for a fixed time of 10[Formula: see text]min, although several other stable IMCs, e.g. Co3Sn2, CoSn, CoSn2, CoSn3 exist in the Co–Sn system at 250∘C according to phase diagram. It is not uncommon that all the thermodynamically stable IMCs do not form in the system due to kinetic reasons. Accordingly, the formation of IMCs through interfacial reaction has been discussed in this paper.

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Li, Shichun. « Atomic phase diagram* ». Progress in Natural Science 14, n^o 2 (1 février 2004) : 113–18. http://dx.doi.org/10.1080/10020070412331343231.

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Dahn, J. R. « Phase diagram ofLixC6 ». Physical Review B 44, n^o 17 (1 novembre 1991) : 9170–77. http://dx.doi.org/10.1103/physrevb.44.9170.

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Ranieri, I. M., S. L. Baldochi et D. Klimm. « The phase diagram – ». Journal of Solid State Chemistry 181, n^o 5 (mai 2008) : 1070–74. http://dx.doi.org/10.1016/j.jssc.2008.02.017.

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