Microstructural evolution in nanoporous gold by thermal and acid treatments

Nanoporous gold was fabricated by dealloying a rolled Au0.3Ag0.7 sheet and the effects of thermal and acid treatments on the porous structure and (111) texture were investigated. Both of the coarsening treatments increased the pore and ligament sizes to approximately 500 nm, whereas the resulting porous structure was very different between the two treatments. After the thermal treatment, the (111) plane was highly oriented in a specific direction; however, the change in the (111) texture after the acid treatment was less pronounced than that after the thermal treatment. There may be difference in migration routes of Au atoms between the two treatments.