Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: 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.

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The categories of this paper are: q-bio
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The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
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The categories of this paper are: nucl-ex
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The categories of this paper are: funct-an
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The categories of this paper are: hep-ex
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The categories of this paper are: mtrl-th
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The categories of this paper are: solv-int
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The categories of this paper are: chem-ph