Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Segregation of the Eu impurity as function of its concentration in the
  melt for growing of the lead telluride doped crystals by the Bridgman method   Behaviour of a rare earth impurity of Eu in the PbTe single crystals grown by
the Bridgman method from the melt with different initial concentrations of
impurity N about 1*10+19 cm-3 and less is investigated with X-ray fluorescent
element analysis, Secondary Neutral Mass Spectroscopy (SNMS), and magnetic
measurements. The impurity distributions along and across the doped ingots are
established. It is revealed that doping impurity enters into the bulk of doped
crystals only if its initial concentration in the melt is high enough,
approximately 1*10+20 cm-3. If this concentration is lower, about 1*10+19 cm-3
and less, the doping Eu impurity is pushed out onto the surface of doped ingot.
The thickness of the doped surface layer is estimated to be in the order of
several microns or somewhat more. The longitudinal distributions of Eu impurity
along the axis of doped ingot for N=1*10+20 cm-3, as well as the transverse one
in the surface layer where entire doping impurity is pushed out for N=1*10+19
cm-3, are strongly non-monotonic. Possible reasons for this unusual behaviour
of Eu doping impurity during the growth of PbTe:Eu crystals from the melt are
analyzed.

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The categories of this paper are: patt-sol
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The categories of this paper are: q-alg
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The categories of this paper are: hep-ph
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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: quant-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: q-bio
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The categories of this paper are: acc-phys
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The categories of this paper are: hep-ex
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The categories of this paper are: math
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The categories of this paper are: adap-org
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The categories of this paper are: chem-ph
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The categories of this paper are: q-fin
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-th