Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: M(H) dependence and size distribution of SPIONs measured by atomic
  magnetometry   We demonstrate that the quasistatic recording of the magnetic excitation
function M(H) of superparamagnetic iron oxide magnetic nanoparticle (SPION)
suspensions by an atomic magnetometer allows a precise determination of the
sample's iron mass content mFe and the particle size distribution.

27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex