| 研究実績の概要 |
Recently our group has reported a new environmentally friendly method for vapor phase dealloying to fabricate novel nanoporous materials. This new method mainly utilizes a difference in vapor pressure between the constituent elements of alloys to selectively remove one of the components with a high partial vapor pressure. However the detailed mechanism of vapor phase dealloying has not been clarified so far.
In this study, we used a Zn-Cu alloy system to examine a difference in diffusion depth for the two elements. By vapor phase dealloying, the nanoporous Cu has been prepared from a Zn-Cu alloy at 350 degreeC and 400 degreeC in low vacuum for different times, ranging from 10 minutes to 110 minutes. The changes of depth and element distribution with the change of time have been characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. For 10 minutes, there are almost no pores in the sample. With the increase of dealloying time, the pores gradually appear. Comparing these samples, we found that the dealloying depth increases with time. It might be possible to understand the dealloying depth’s functional dependence on time and temperature by dissolution model.
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