Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cu Nuclear Quadrupole Resonance Study of the Spin-Peierls Compound
  Cu1-xMgxGeO3: A Possibility of Precursory Dimerization   We report on a zero-field 63Cu nuclear quadrupole resonance (NQR) study of
nonmagnetic Mg impurity substituted Cu1-xMgxGeO3 (single crystals; the
spin-Peierls transition temperature Tsp~14, 13.5, and 11 K for x=0, 0.0043, and
0.020) in a temperature range from 4.2 K to 250 K. We found that below T*~77 K,
Cu NQR spectra are broadened and nonexponential Cu nuclear spin-lattice
relaxation increases for undoped and more remarkably for Mg-doped samples. The
results indicate that random lattice distortion and impurity-induced spins
appear below T*, which we associate with a precursor of the spin-Peierls
transition. Conventional magnetic critical slowing down does not appear down to
4.2 K below Tsp.

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The categories of this paper are: econ
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The categories of this paper are: eess
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The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
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The categories of this paper are: math-ph
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The categories of this paper are: q-alg
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The categories of this paper are: nlin
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The categories of this paper are: chem-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: mtrl-th
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The categories of this paper are: hep-lat
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The categories of this paper are: comp-gas
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The categories of this paper are: nucl-ex
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The categories of this paper are: astro-ph
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The categories of this paper are: cmp-lg