In situ imaging of dealloying during nanoporous gold formation by transmission X-ray microscopy

被引：44

作者：

Chen-Wiegart, Yu-chen Karen ^{[1
,2
]}

Wang, Steve ^{[2
]}

Lee, Wah-Keat ^{[2
]}

McNulty, Ian ^{[2
]}

Voorhees, Peter W. ^{[1
]}

Dunand, David C. ^{[1
]}

机构：

[1] Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA

[2] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA

来源：

ACTA MATERIALIA | 2013年 / 61卷 / 04期

关键词：

TXM; X-ray synchrotron radiation; Metal foam; MORPHOLOGICAL CHARACTERIZATION; CU; EVOLUTION;

D O I：

10.1016/j.actamat.2012.10.017

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The dealloying process is directly imaged, for the first time, by using transmission X-ray microscopy for the case of an Ag-30 at.% Au wire dealloyed under free corrosion in nitric acid. The propagation of a sharp dealloying front separating the alloy from nanoporous Au was observed by two-dimensional real-time in situ imaging at 30 nm resolution and measured in detail in three dimensions by an ex situ nanotomography technique at fixed time intervals. The rate of the dealloying front propagation is independent of the dealloying time up to a 3 mu m depth, indicating that the dealloying process to this depth is dominated by interfacial effects (i.e. gold surface diffusion and/or silver dissolution) rather than long-range transport effects (i.e. diffusion of acid and corrosion product in and out of the porous layer). The constant dealloying rate corresponds to a constant silver flux and a constant current density, even though the potential might be fluctuating under free corrosion conditions and the interfacial area is shrinking as a function of time. Free corrosion in this system generates a high current density, implying it is driven by a chemical potential difference that is much higher than the critical potential. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

引用

页码：1118 / 1125

页数：8

共 37 条

[1]

[Anonymous], 1998, SMITHELLS METALS REF

[2]

Balluffi RW, 2005, KINETICS OF MATERIALS, P1

[3] Surface-chemistry-driven actuation in nanoporous gold [J].

Biener, J. ;

Wittstock, A. ;

Zepeda-Ruiz, L. A. ;

Biener, M. M. ;

Zielasek, V. ;

Kramer, D. ;

Viswanath, R. N. ;

Weissmueller, J. ;

Baeumer, M. ;

Hamza, A. V. .

NATURE MATERIALS, 2009, 8 (01) :47-51

[4]

Chen Y, 2008, NANOTECHNOLOGY, V19

[5] Hard-x-ray microscopy with Fresnel zone plates reaches 40 nm Rayleigh resolution [J].

Chu, Y. S. ;

Yi, J. M. ;

De Carlo, F. ;

Shen, Q. ;

Lee, Wah-Keat ;

Wu, H. J. ;

Wang, C. L. ;

Wang, J. Y. ;

Liu, C. J. ;

Wang, C. H. ;

Wu, S. R. ;

Chien, C. C. ;

Hwu, Y. ;

Tkachuk, A. ;

Yun, W. ;

Feser, M. ;

Liang, K. S. ;

Yang, C. S. ;

Je, J. H. ;

Margaritondo, G. .

APPLIED PHYSICS LETTERS, 2008, 92 (10)

[6] Bulk gold with hierarchical macro-, micro- and nano-porosity [J].

Cox, Marie E. ;

Dunand, David C. .

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 2011, 528 (06) :2401-2406

[7] Nanoporous gold leaf: "Ancient technology"/advanced material [J].

Ding, Y ;

Kim, YJ ;

Erlebacher, J .

ADVANCED MATERIALS, 2004, 16 (21) :1897-+

[8]

Ding Y., 2009, MRS BULL, V34, P8

[9] Preparation, structure, and optical properties of nanoporous gold thin films [J].

Dixon, Matthew C. ;

Daniel, Thomas A. ;

Hieda, Mitsunori ;

Smilgies, Detlef M. ;

Chan, Moses H. W. ;

Allara, David L. .

LANGMUIR, 2007, 23 (05) :2414-2422

[10] Probing the dealloying critical potential - Morphological characterization and steady-state current behavior [J].

Dursun, A ;

Pugh, DB ;

Corcoran, SG .

JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 2005, 152 (02) :B65-B72

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