Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Superconducting Mechanism through direct and redox layer doping in
  Pnictides   The mechanism of superconductivity in pnictides is discussed through direct
doping in superconducting FeAs and also in charge reservoir REO layers. The
un-doped SmFeAsO is charge neutral SDW (Spin Density Wave) compound with
magnetic ordering below 150 K. The Superconducting FeAs layers are doped with
Co and Ni at Fe site, whereas REO layers are doped with F at O site. The
electron doping in SmFeAsO through Co results in superconductivity with
transition temperature (Tc) maximum up to 15 K, whereas F doping results in Tc
upto 47 K in SmFeAsO. All these REFe/Co/NiAsO/F compounds are iso-structural to
ZrCuSiAs structure. The samples are crystallized in a tetragonal structure with
space group P4/nmm. Variation of Tc with different doping routes shows the
versatility of the structure and mechanism of occurrence of superconductivity.
It seems doping in redox layer is more effective than direct doping in
superconducting FeAs layer.

24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg