The temperature and pressure dependences of Ge in pure Al were studied by using radiotracer and microtome serial sectioning methods. Oxide effects were avoided by ion-implanting 71Ge, or by sputter-cleaning the Al before evaporating a thin 71Ge layer. It was found that Ge was a normal diffuser, and the data could be described by:

D(cm2/s) = 3.39 x 10-1exp[-28.4(kcal/mol)/RT]

The activation volume was equal to 1.16 of an atomic volume at 764K, and to 1.24 of an atomic volume at 841K. The results suggested that Ge diffusion proceeded via vacancies.

A.Thurer, G.Rummel, T.Zumkley, K.Freitag, H.Mehrer: Physica Status Solidi A, 1995, 149[1], 535-47