Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Soft Mode Anomalies in the Perovskite Relaxor Pb(Mg1/3Nb2/3)O3   Neutron inelastic scattering measurements of the polar TO phonon mode in the
cubic relaxor Pb(Mg1/3Nb2/3)O3, at room temperature, reveal anomalous behavior
similar to that recently observed in the Pb(Zn1/3Nb2/3)_{0.92}Ti_{0.08}O3
system in which the optic branch appears to drop precipitously into the
acoustic branch at a finite value of the momentum transfer q = 0.20
1/Angstroms, measured from the zone center. By contrast, a recent neutron study
showed that PMN exhibits a normal TO phonon dispersion at 800 K. We speculate
this behavior is common to all relaxor materials and is the result of the
presence of nanometer-scale polarized domains in the crystal that form below a
temperature Td, which effectively prevent the propagation of long wavelength (q
= 0) phonons.

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The categories of this paper are: atom-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: eess
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The categories of this paper are: stat
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The categories of this paper are: math-ph
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The categories of this paper are: funct-an
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The categories of this paper are: hep-th
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The categories of this paper are: ao-sci
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The categories of this paper are: gr-qc
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The categories of this paper are: mtrl-th
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The categories of this paper are: hep-ex
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The categories of this paper are: astro-ph
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The categories of this paper are: bayes-an