Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Doping effects of Cr on the physical properties of
  BaFe$_{1.9-x}$Ni$_{0.1}$Cr$_{x}$As$_{2}$   We present a systematic study on the heavily Cr doped iron pnictides
BaFe$_{1.9-x}$Ni$_{0.1}$Cr$_{x}$As$_{2}$ by using elastic neutron scattering,
high-resolution synchrotron X-ray diffraction (XRD), resistivity and Hall
transport measurements. When the Cr concentration increases from $x=$ 0 to 0.8,
neutron diffraction experiments suggest that the collinear antiferromagnetism
persists in the whole doping range, where the N\'{e}el temperature $T_N$
coincides with the tetragonal-to-orthorhombic structural transition temperature
$T_s$, and both of them keeps around 35 K. The magnetic ordered moment, on the
other hand, increases within increasing $x$ until $x=$ 0.5, and then decreases
with further increasing $x$. Detailed refinement of the powder XRD patterns
reveals that the Cr substitutions actually stretch the FeAs$_4$ tetrahedron
along the $c-$axis and lift the arsenic height away Fe-Fe plane. Transport
results indicate that the charge carriers become more localized upon Cr doping,
then changes from electron-type to hole-type around $x=$ 0.5. Our results
suggest that the ordered moment and the ordered temperature of static magnetism
in iron pnictides can be decoupled and tuned separately by chemical doping.

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The categories of this paper are: math
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The categories of this paper are: cs
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The categories of this paper are: nlin
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The categories of this paper are: cmp-lg
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The categories of this paper are: gr-qc
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The categories of this paper are: q-fin
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The categories of this paper are: econ
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The categories of this paper are: adap-org
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The categories of this paper are: q-alg
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The categories of this paper are: solv-int
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: astro-ph
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The categories of this paper are: eess