Self-Diffusion in Gold

Makin, S. M.; Rowe, Albert H.; LeClaire, A. D.

doi:10.1088/0370-1301/70/6/301

Cited by 131 publications

(31 citation statements)

References 6 publications

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“…This vacuum-annealing activation energy was nearly equal to that of lattice diffusion of gold (174.6 kJ/mol). 11,12) We presume that this difference arose as follows: In air, the surface adsorption of gas molecules promotes the surface diffusion of Au adatoms on NPG, which is the dominant mechanism of thermal coarsening in air (i.e. gas).…”

Section: ¹1mentioning

confidence: 99%

Environment-Sensitive Thermal Coarsening of Nanoporous Gold

et al. 2015

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In order to investigate environmental effects on the ligament/pore coarsening of nanoporous gold (NPG), we studied the thermal coarsening of NPG both in air and vacuum by ex situ observation, and found that it has high structural stability against heat treatment in vacuum. To clarify the nature of this phenomenon, we investigated the thermal coarsening of NPG by in situ environmental transmission electron microscopy. At an elevated temperature (400°C), the coarsening of ligaments/pores was triggered by introducing either pure N 2 or O 2 gas into the transmission electron microscopy (TEM) chamber (but not by Ar gas). We thus conclude with a discussion on the mechanism for thermal coarsening of NPG.

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Section: ¹1mentioning

confidence: 99%

Environment-Sensitive Thermal Coarsening of Nanoporous Gold

et al. 2015

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“…26,29) The selfdiffusion coefficient of Au is slightly smaller than that of Cu. 27) Because the difference in the atomic radius between Cu and Ag, and Cu and Au is about 13%, the incorporation of Ag/Au atoms into the Cu lattice difficult. On the other hand, the self-diffusion coefficients of Pt-group (G-II) elements are smaller than those of Cu, 28,30) and the formation of the crystalline phase of G-II elements (Ni, Pd, Pt) was interrupted by the diffusion of Cu atoms.…”

Section: Effects Of Lsdms On Surface Diffusionmentioning

confidence: 99%

Refinement of Nanoporous Copper: A Summary of Micro-Alloying of Au-Group and Pt-Group Elements

2014

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The micro-alloying of 1 at% metals of Au-Group (Ag, Au) and the Pt-Group (Ni, Pd, Pt) with the Ti 60 Cu 40 amorphous alloy resulted in the formation of fine nanoporous copper (NPC) in the order of 628 nm. The smallest characteristic pore size of opencell nanoporous fcc Cu was 7 and 6 nm after dealloying the amorphous Ti 60 Cu 39 Pd 1 and Ti 60 Cu 39 Pt 1 precursor alloys for 43.2 ks in 0.03 M HF solution, while NPC had a pore size of 39 nm after dealloying the amorphous Ti 60 Cu 40 precursor alloy. On the basis of TEM micrographs, the refining factor increased approximately from 4 for the Ti 60 Cu 39 Ag 1 precursor alloy to 1780 for the Ti 60 Cu 39 Pt 1 precursor alloy. The refinement was attributed to the dramatic decrease in the surface diffusivity during dealloying. The refinement efficiency of the micro-alloying of the Pt-group elements was higher than that of the Au-group elements. The homogeneous distribution of additives in both of the amorphous precursor alloys and the final stabilized NPCs played a key role in refining the NPCs. This strategy may contribute to the fabrication of cost-effective nanoporous metals with a nanoporosity comparable to that of nanoporous Au, Pd and Pt catalysts.

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“…The method has the advantage of simplicity providing the layers removed by lathing (Makin et al 1957), or other techniques (Liu & Drickamer 1954: Neiman & Chinear 1954, are carried out with sufficient care and precision. The method of removing layers can introduce an error if the new face is not exactly parallel to the specimen's original face (Shim et al 1953).…”

Section: 21 the Sectioning Techniquementioning

confidence: 99%

“…In diffusion studies in which the specimen undergoes heating and cooling cycles, before and after the diffusion anneal, a correction to the annealing time is generally applied in order to find the true annealing time (Makin et al 1957: Shewman 1963. The practice employed in this study, of virtually instantaneous introduction and withdrawal of the specimen into and from the furnace hot zone (see Section 4.4.3), precludes the necessity of applying such a correction.…”

Section: Errors In the Annealing Time (T)mentioning

confidence: 99%