Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pressure effects in hollow and solid iron oxide nanoparticles   We report a study on the pressure response of the anisotropy energy of hollow
and solid maghemite nanoparticles. The differences between the maghemite
samples are understood in terms of size, magnetic anisotropy and shape of the
particles. In particular, the differences between hollow and solid samples are
due to the different shape of the nanoparticles and by comparing both pressure
responses it is possible to conclude that the shell has a larger pressure
response when compared to the core.

36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc