1204.2992 (D. Spemann et al.)

Comment on: "Revealing common artifacts due to ferromagnetic inclusions
in highly oriented pyrolytic graphite", by M. Sepioni, R.R. Nair, I.-Ling
Tsai, A.K. Geim and I.V. Grigorieva, EPL 97 (2012) 47001    [PDF]

D. Spemann, M. Rothermel, P. Esquinazi, M. Ramos, Y. Kopelevich, H. Ohldag

This comment addresses several issues in the paper by Sepioni et al., where it is stated that the ferromagnetism in pristine highly oriented pyrolytic graphite (HOPG) reported by several groups in the previous years is most likely due to impurity contamination. In this comment, clear arguments are given why this statement is not justified. Furthermore, it is pointed out, that there are already measurements using element-sensitive microscopic techniques, e.g. X-ray Magnetic Circular Dichroism (XMCD) that directly proved the intrinsic origin of the ferromagnetism in graphite, also in pristine HOPG.

View original: http://arxiv.org/abs/1204.2992