We studied magnetic properties of thin Ge:Mn films obtained by implantation of Mn + ions into a single crystalline bulk germanium. In the net magnetic moment we were able to separate contributions originating from dispersed Mn 2+ ions, ferromagnetic Mn 5 Ge 3 precipitates, and regions of the germanium matrix enriched with diluted manganese-Mn m Ge n alloys. In the subsystem of dispersed Mn 2+ ions we observed a percolation transition into the ferromagnetic state at T Յ 13 K. Collective excitations, standing spin waves, were also detected below this temperature. The main parameters of the exchange interaction obtained from the analysis of the experimental spin-wave resonance data are consistent with results acquired from static magnetic measurements as well as with theoretical estimations for a percolation ferromagnet. Thus, we demonstrate that low-temperature magnetic properties of group IV magnetic semiconductor can be successfully explained within a magnetic polaron model.

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