Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Neutron powder diffraction study on the iron-based nitride
  superconductor ThFeAsN   We report neutron diffraction and transport results on the newly discovered
superconducting nitride ThFeAsN with $T_c=$ 30 K. No magnetic transition, but a
weak structural distortion around 160 K, is observed cooling from 300 K to 6 K.
Analysis on the resistivity, Hall transport and crystal structure suggests this
material behaves as an electron optimally doped pnictide superconductors due to
extra electrons from nitrogen deficiency or oxygen occupancy at the nitrogen
site, which together with the low arsenic height may enhance the electron
itinerancy and reduce the electron correlations, thus suppress the static
magnetic order.

1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an