Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Structural aspects of metamagnetism in Ca_{2-x}Sr_{x}RuO_4 (0.2 < x <
  0.5): field tuning of orbital occupation   The crystal structure of Ca_{2-x}Sr_xRuO_4 with 0.2 < x < 1.0 has been
studied by diffraction techniques and by high resolution capacitance
dilatometry as a function of temperature and magnetic field. Upon cooling in
zero magnetic field below about 25 K the structure shrinks along the
c-direction and elongates in the a, b planes (0.2 < x < 1.0), whereas the
opposite occurs upon cooling at high-field (x = 0.2 and 0.5). These findings
indicate an orbital rearrangement driven by temperature and magnetic field,
which accompanies the metamagnetic transition in these compounds.

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The categories of this paper are: hep-ex
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg