Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetotransport and thermal properties characterization of 55 K
  superconductor SmFeAsO0.85F0.15   Correlation between structural/microstructural and magneto-thermal transport
properties of FeAs-based SmFeAsO and SmFeAsO0.85F0.15 has been studied in
detail. The Rietveld analysis of room temperature powder X-ray diffraction
(XRD) data reveals that both the samples are single phase, with very small
amount of rare earth impurity in the F doped compound. Electron microscopic
investigations show that compounds have layered morphology and structure, with
the individual grains being surrounded by amorphous layers. The average grain
boundary thickness is ~5 nm. The F free material is found to be magnetic and
shows the appearance of Fe spin density wave (SDW) like order at T = 150 K. The
F doped compound (SmFeAsO0.85F0.15) shows the occurrence of superconductivity
at Tc(R=0, H=0)- 55 K, which decreases to 42 K at magnetic field (H) of 13 kOe.
The superconducting transition was also confirmed by DC magnetization and AC
susceptibility measurements. The intra-grain critical current density (Jc)
calculated using the Bean critical state model is found to be around 5.26 x
10^4 A/cm2 at 5 K in zero field (H=0). The dependence of thermally activated
flux flow energy (U/KB) on the applied magnetic field has been observed. AC
susceptibility measurements at different amplitude of applied AC drive field
confirm the granular nature of the superconducting compound. is confirmed. Both
Fe (SDW) at 150K for SmFeAsO and 55K superconductivity in case of
SmFeAsO0.85F0.15 sample has confirmed by Specific heat [Cp(T)] measurement too.
Further Sm orders anti-ferro-magnetically at 4.5K for non-superconducting and
at 3.5K for superconducting samples, also the entropy change is reduced
significantly for the later than the former. Summarily complete physical
property characterization for both non-superconducting SmFeAsO and 55K
superconductor SmFeAsO0.85F0.15 samples is provided and discussed in the
current article.

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The categories of this paper are: acc-phys
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The categories of this paper are: math-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: patt-sol
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The categories of this paper are: nlin
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The categories of this paper are: nucl-th
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The categories of this paper are: supr-con
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The categories of this paper are: q-bio
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The categories of this paper are: gr-qc
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The categories of this paper are: stat
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The categories of this paper are: chao-dyn
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The categories of this paper are: chem-ph
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The categories of this paper are: math
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The categories of this paper are: plasm-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: comp-gas