We have studied the magnetization of vertically aligned graphene nanoflakes irradiated with nitrogen ions of 100 KeV energy and doses in the range 10^11- 10^17 ions/cm2. The non-irradiated graphene nanoflakes show a paramagnetic contribution, which is increased progressively by ion irradiation at low doses up to 10^15 /cm^2. However, further increase on implantation dose reduces the magnetic moment which coincides with the onset of amorphization as verified by both Raman and X-ray photoelectron spectroscopic data. Overall, our results demonstrate the absence of ferromagnetism on either implanted or unimplanted samples from room temperature down to a temperature of 5K
@article{arxiv.1109.1483,
title = {Irradiation Enhanced paramagnetism on graphene nanoflakes},
author = {Andreas Ney and Pagona Papakonstantinou and Ajay Kumar and Nai-Gui Shang and Nianhua Peng},
journal= {arXiv preprint arXiv:1109.1483},
year = {2011}
}