Application of microsectioning technique using ion-beam sputtering for low temperature tracer diffusion in solids

The direct method for the measurements of small diffusion coefficients at low temperature by microsectioning using ion-beam sputtering is described. The ion-beam sputtering device for taking thin sections from solid-state diffused sample is introduced. The features include the use of a duo-plasmatron type ion gun, high yield chamber geometry and a catcher-foil camera capable of taking about 30 sections without interrupting ionbeam. The small impurity-diffusion coefficients for 198Au in copper single crystal are measured in the low-temperature range between 633 and 982 K where mechanical sectioning can not be used. The results are compared with the data by Rutherford backscattering spectrometry and the self-diffusivities of copper in the same temperature range. The existence of non-linear Arrhenius behavior for the impurity-diffusion is also discussed in combination with the data in high-temperature range obtained using mechanical sectioning technique. (author)