Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ferromagnetism in Fe-doped Ba6Ge25 Chiral Clathrate   We have successfully synthesized a Ba6Ge25 clathrate, substituting 3 Fe per
formula unit by Ge. This chiral clathrate has Ge sites forming a framework of
closed cages and helical tunnel networks. Fe atoms randomly occupy these sites,
and exhibit high-spin magnetic moments. A ferromagnetic transition is observed
with Tc = 170 K, the highest observed Tc for a magnetic clathrate. However, the
magnetic phase is significantly disordered, and exhibits a transformation to a
re-entrant spin glass phase. This system has a number of features in common
with other dilute magnetic semiconductors.

31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga