Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Anomalous Skin Effect in Single Crystal Relaxor Ferroelectric
  PZN-xPT and PMN-xPT   X-ray and neutron scattering studies of the lead-based family of perovskite
relaxors PZN-$x$PT and PMN-$x$PT have documented a highly unusual situation in
which the near-surface region of a single crystal can exhibit a structure that
is different from that of the bulk when cooled to low temperatures. The
near-surface region, or "skin" can also display critical behavior that is
absent in the crystal interior, as well as a significantly different lattice
spacing. By varying the incident photon energy, and thus the effective
penetration depth, x-ray measurements indicate a skin thickness of order 10
$\mu$m to 50 $\mu$m for PZN-$x$PT samples with $0 \le x \le 8$%. Neutron
residual stress measurements on a large PMN single crystal reveal a uniform
lattice spacing within the bulk, but an increased strain near the surface. The
presence of this skin effect has led to incorrect phase diagrams for both the
PZN-$x$PT and PMN-$x$PT systems and erroneous characterizations of the nature
of the relaxor state.

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The categories of this paper are: supr-con
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The categories of this paper are: atom-ph
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The categories of this paper are: solv-int
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The categories of this paper are: q-alg
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The categories of this paper are: physics
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The categories of this paper are: nucl-th
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The categories of this paper are: eess
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: ao-sci
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The categories of this paper are: comp-gas
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The categories of this paper are: patt-sol
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The categories of this paper are: quant-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: nlin