Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Synthesis, Structure and Magnetic Properties of New Layered
  Iron-Oxychalcogenide Na2Fe2OSe2   A new layered iron-oxychalcogenide Na2Fe2OSe2 has been synthesized and
structurally characterized by powder X-ray diffraction. The structure is formed
by alternate stacking of the newly discovered [Fe2OSe2] blocks and double
layers of Na. Conductivity study shows that Na2Fe2OSe2 is a semiconductor with
activation energy of 0.26 eV. Magnetic susceptibility and heat capacity
measurements reveal an antiferromagnetic phase transition occurs at TN=73 K. A
broad maximum of magnetic susceptibility and a slow decay of the specific heat
above TN, arises as a result of two-dimensional short-range spin correlation.

13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat