Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin-transfer mechanism of ferromagnetism in polymerized fullerenes: $Ab
  initio$ calculations   A mechanism of the high temperature ferromagnetism in polymerized fullerenes
is suggested. It is assumed that some of the C$_{60}$ molecules in the crystal
become magnetically active due to spin and charge transfer from the
paramagnetic impurities (atoms or groups), such as hydrogen, fluorine, hydroxyl
group OH, amino group NH$_2$, or methyl group CH$_3$, dispersed in the
fullerene matrix. The exchange interaction between the spins localized on the
magnetically active fullerenes is evaluated using \textit{ab initio}
calculations. The nearest neighbour and next nearest neighbour exchange
interaction is found to be in the range $0.1\div 0.3 $ eV, that is, high enough
to account for the room temperature ferromagnetism.

16
The categories of this paper are: stat
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci