Swift heavy ion induced formation of preferentially oriented Au0.6Ge0.4 alloy

Formation of Au0.6Ge0.4 alloy on Si (1 0 0) substrate has been observed upon irradiating Au/Ge bilayer with 120 MeV Au ions and subsequent vacuum annealing at 360 °C. Transmission electron microscopy measurements on irradiated and vacuum annealed Au/Ge samples show a possibility of formation of oriented Au0.6Ge0.4 alloy, in agreement with X-ray diffraction data. These measurements reveal that although 120 MeV Au irradiation alone can not lead to a large scale mixing, it acts as a seed by forming nanoislands of Au0.6Ge0.4 alloy. Further post-irradiation annealing leads to vigorous intermixing of Au and Ge followed by the formation of large, closely packed and oriented Au0.6Ge0.4 islands. These results have been discussed on the basis of irradiation induced effects followed by subsequent thermal annealing. [Copyright &y& Elsevier]