Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Correlated pressure effects on structure and superconductivity in
  LaFeAsO0.9F0.1   We have studied the structural and superconductivity properties of the
compound LaFeAsO0.9F0.1 under pressures up to 32GPa using synchrotron radiation
and diamond anvil cells. We obtain an ambient pressure bulk modulus K_0 =
78(2)GPa, compressibility comparable to some cuprates. At high pressures, the
sample is in the overdoped region, with a linear decrease with pressure
variation of the superconducting transition temperature.

32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas