Interface modification in Co/Ge bilayer using swift heavy ions.

We report on interface modification in Co/Ge bilayer system using 100 MeV Au7+ ion irradiation at different temperatures and fluences. Irradiation induced changes occurring across the Co/Ge interface are studied by Rutherford backscattering spectrometry and cross-sectional transmission electron microscopy. Although Au irradiation at low temperature does not show any interface mixing, formation of a thin (∼3–4 nm) Co–Ge alloy layer has been observed after room temperature irradiation to a fluence of 1×1014 ions cm-2. This mixing has been discussed on the basis of synergetic effects of nuclear and electronic energy loss processes in the bilayer system. [ABSTRACT FROM AUTHOR]