We present an original technique for growing large fullerene onions: c
arbon-ion implantation at high temperature into copper substrates. Use
d for carbon film growth (diamond or turbostratic carbon), this method
is based on the immiscibility of carbon into copper and can produce a
n important density of giant carbon onions with size up to some microm
etres which is the largest size observed up to now. We characterize th
ese giant fullerenes by TEM, HRTEM and for the fi rst time with AFM. O
n the basis of both experimental and numerical results we propose a me
chanism of formation of the carbon onions during the implantation proc
ess.