Published online by Cambridge University Press: 15 February 2011
After a relatively low dose Xe+ irradiation (∼ 2 × 1015 Xe/cm2), an initially discrete multilayered film of average composition Au7Si3 transforms to a uniform layer and forms a metastable phase. This is the well known ion mixing process. The same samples were subjected to higher dose irradiation (> 4 × 1015 Xe/cm2). It was found that the Si migrates to the sample surface and forms a nonuniform depth profile in BS spectra. At the same time, the metastable phase dissociates into Au and Si phases. As this process is opposite to that of ion mixing, we suggest to name this process ion demixing. These observations demonstrate that ion mixing and ion demixing can both occur in the same system, if it is properly chosen. Possible mechanism responsible for these processes are discussed.
Permanent Address: Qinghua University, Beijing, The People's Republic of China.
Permanent Address: Institute of Nuclear Research, Warszawa, Hoza 69, Poland.