Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Doping Effects on the two-dimensional Spin Dimer Compound
  $SrCu_2(BO_3)_2$   A series of compounds M$_{0.1}$Sr$_{0.9}$Cu$_2$(BO$_3$)$_2$ with Sr
substituted by M=Al, La, Na and Y were prepared by solid state reaction. XRD
analysis showed that these doping compounds are isostructural to
SrCu$_2$(BO$_3$)$_2$. The magnetic susceptibility from 1.9K to 300K in an
applied magnetic field of 1.0T and the specific heat from 1.9K to 25K in
applied fields up to 14T were measured. The spin gap is deduced from the low
temperature susceptibility as well as the specific heat. It is found that the
spin gap is strongly suppressed by magnetic fields. No superconductivity is
observed in all four samples.

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The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
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The categories of this paper are: atom-ph
2
The categories of this paper are: math
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
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The categories of this paper are: supr-con
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The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: dg-ga
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The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom