Nanoporous gold (np-Au) thin films were fabricated from Au-Ag alloy films sputtered onto substrates. At several stages of dealloying, the evolution of the microstructure and Ag content were analyzed and stress in the np-Au thin films was measured. A nanoporous structure evolved almost immediately throughout the film thickness, and the ligament width coarsened during further dealloying, with a time dependence of t1/8. The initial alloy films, which contained 25 at. pct Au, became stress free after extended dealloying and during thermal cycling up to 200 °C. Preferential dissolution caused cracking at grain boundaries, which accommodated a portion of the volume contraction from dealloying, but the films nonetheless remained attached to their substrates.
|Number of pages
|Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
|Published - Nov 2008
Bibliographical noteFunding Information:
The authors thank Ms. Sofie Burger for her assistance with the measurement of the ligament widths and Mr. Larry Rice for his support in using the SEM. The authors also acknowledge the Donors of the American Chemical Society Petroleum Research Fund (Grant No. 43324-G10), for support of this research.
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys