Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Influence of Na-doping and sintering temperature on increasing
  Bi2Sr2CaCu2O8 superconducting phase content in powder form materials   This paper proposes a systematic way to explore the effects of Na on Bi-2212
phase formation. The influence of sodium metal is correlated with the 2212
fraction formed in the sample. The effect on the sintering temperature and the
importance of the substitution site is studied. Samples are characterized by
X-ray diffraction analysis (XRD). Results clearly show that the 2212 phase
content is enhanced and sintering temperatures can be lowered with regard to
the undoped samples.

22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom