Ling W L, Bartelt N C, Pohl K, de la Figuera J, Hwang R Q, McCarty K F
Sandia National Laboratories, Livermore, California 94551-0969, USA.
Phys Rev Lett. 2004 Oct 15;93(16):166101. doi: 10.1103/PhysRevLett.93.166101. Epub 2004 Oct 13.
We find that less than 0.01 monolayer of S can enhance surface self-diffusion on Cu(111) by several orders of magnitude. The measured dependence of two-dimensional island decay rates on S coverage (theta(S)) is consistent with the proposal that Cu3S3 clusters are responsible for the enhancement. Unexpectedly, the decay and ripening are diffusion limited with very low and very high theta(S) but not for intermediate theta(S). To explain this result we propose that surface mass transport in the intermediate region is limited by the rate of reaction to form Cu3S3 clusters on the terraces.
我们发现，小于0.01单层的硫能将铜（111）表面的自扩散提高几个数量级。所测量的二维岛衰减速率对硫覆盖率（θ(S)）的依赖性与以下提议一致，即Cu3S3团簇是增强作用的原因。出乎意料的是，在极低和极高的θ(S)时，衰减和熟化受扩散限制，而在中间的θ(S)时则不然。为了解释这一结果，我们提出中间区域的表面质量传输受在台面上形成Cu3S3团簇的反应速率限制。
