Presently, temporary metallic implants, like bone nails, based on stainless steel and titanium are widely employed. Since, these implants have to be removed after fracture healing, there are reflections about bio-degradable implants based on magnesium. To ensure that the magnesium based implant is stable during the healing process, a biocompatible diffusion barrier to the surrounding tissue is required. For this task, hydrogenated amorphous diamond-like carbon (DLC) may be a potential candidate. Within this work, hydrogen containing DLC coatings were produced by reactive unbalanced magnetron sputtering in an argon/acetylene (Ar/C2H2) atmosphere with an increasing C2H2/Ar – flow ratio. These coatings were studied concerning their structure and mechanical properties. The following investigations were done: coating thickness measurements, Elastic Recoil Detection Analysis, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy for structure information as well as nanoindentation and residual stress measurements to determine mechanical properties. The coatings show an amorphous and dense structure with a smooth surface as well as a decreasing nanohardness (from ~25 to 8 GPa) and Young’s modulus (from ~187 to 55 GPa) with an increasing C2H2/Ar – flow ratio, which indicates an increasing graphitic film structure.