A comparison of the magnetic properties of Proton- and Iron-implanted   graphite
  In this work we have investigated the changes of the magnetic properties of highly oriented pyrolytic graphite samples after irradiation either with $\sim 3 \times 10^{14}$ protons or $ 3.5 \times 10^{13} ... 3.5 \times 10^{14}$ iron ions with energies in the MeV range. Our results show that iron and proton irradiations can produce similar paramagnetic contributions depending on the implantation temperature. However, only protons induce a ferromagnetic effect. 
J. Barzola-Quiquia, R. H\"ohne, M. Rothermel, A. Setzer, P. Esquinazi,   and V. Heera