Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Insulator-metal transition shift related to magnetic polarons in
  La0.67-xYxCa0.33MnO3   The magnetic transport properties have been measured for La0.67-xYxCa0.33MnO3
(0 <= x <= 0.14) system. It was found that the transition temperature Tp almost
linearly moves to higher temperature as H increases. Electron spin resonance
confirms that above Tp, there exist ferromagnetic clusters. From the magnetic
polaron point of view, the shift of Tp vs. H was understood, and it was
estimated that the size of the magnetic polaron is of 9.7~15.4 angstrom which
is consistent with the magnetic correlation length revealed by the small-angle
neutron-scattering technique. The transport properties at temperatures higher
than Tp conform to the variable-range hopping mechanism.

35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
16
The categories of this paper are: stat