Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tailoring the magnetism of GaMnAs films by ion irradiation   Ion irradiation of semiconductors is a well understood method to tune the
carrier concentration in a controlled manner. We show that the ferromagnetism
in GaMnAs films, known to be hole-mediated, can be modified by He ion
irradiation. The coercivity can be increased by more than three times. The
magnetization, Curie temperature and the saturation field along the
out-of-plane hard axis all decrease as the fluence increases. The electrical
and structural characterization of the irradiated GaMnAs layers indicates that
the controlled tailoring of magnetism results from a compensation of holes by
generated electrical defects.

2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
3
The categories of this paper are: physics
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga