  In electron irradiated Ge$_{0.98}$Si$_{0.02}$, In-vacancy and In-interstitial
complexes were observed in analogy with defects in pure Ge. Isochronal
annealing measurements reveal that the temperature of dissociation of In-defect
complexes deviate from pure Ge subjected to identical e-irradiation, which is
explained on the basis of strain induced by undersized silicon atoms affecting
the binding energy of In-V and In-I complexes. Besides the pairing with
intrinsic defects the interaction of In with Si atoms is observed resulting in
several different configurations. Complementary experiments performed in
Ge$_{0.98}$Si$_{0.02}$ and Ge$_{0.94}$Si$_{0.06}$ elucidate the attractive
interaction between In and Si.
