We report on emission channeling experiments using the radioactive isotope Cu-67 implanted into single crystalline i-Ge at a fluence of 2.4 x 10(12) cm(-2). The lattice location of Cu-67 was determined from the angular-dependent beta(-) emission yield, which was measured by means of a position-sensitive detector around the <1 1 1>, <1 0 0> and <1 1 0> directions. We find that already in the as-implanted state a considerable fraction of Cu (20-25%) occupies ideal substitutional lattice positions, a similar fraction is located on positions that are displaced around 0.5-0.6Angstrom from substitutional sites. Following annealing at 300degreesC for 10 min, the substitutional fraction of implanted Cu increased to 45% while the fraction of displaced Cu decreased to 23%. Upon further annealing at 400degreesC, channeling effects disappeared completely and around 10% of Cu-67 diffused out of the Ge sample. From this we can estimate the activation energy for dissociation of substitutional Cu to be around 1.6-1.9 eV. (C) 2003 Elsevier B.V. All rights reserved.