Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetic structure and spin dynamics of quasi-one-dimensional spin-chain
  antiferromagnet BaCo2V2O8   We report a neutron diffraction and muon spin relaxation muSR study of static
and dynamical magnetic properties of BaCo2V2O8, a quasi-one-dimensional
spin-chain system. A proposed model for the antiferromagnetic structure
includes: a propagation vector k_AF = (0, 0, 1), independent of external
magnetic fields for fields below a critical value H_c(T). The ordered moments,
of 2.18 \mu_B per Co ion, are aligned along the crystallographic c-axis. Within
the screw chains, along the c axis, the moments are arranged
antiferromagnetically. In the basal planes the spins are arranged
ferromagnetically (forming zig-zags paths) along one of the axis and
antiferromagnetically along the other. The temperature dependence of the
sub-lattice magnetization is consistent with the expectations of the 3D Ising
model. A similar behavior is observed for the internal static fields at
different muon stopping sites. Muon time spectra measured at weak longitudinal
fields and temperatures much higher than T_N can be well described using a
single muon site with an exponential muon spin relaxation that gradually
changes into an stretched exponential on approaching T_N. The
temperature-induced changes of the relaxation suggest that the Co fluctuations
dramatically slow down and the system becomes less homogeneous as it approaches
the antiferromagnetic state.

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The categories of this paper are: econ
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The categories of this paper are: cs
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The categories of this paper are: acc-phys
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The categories of this paper are: stat
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The categories of this paper are: chem-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-fin
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The categories of this paper are: hep-lat
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The categories of this paper are: math-ph
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The categories of this paper are: solv-int
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The categories of this paper are: alg-geom
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The categories of this paper are: funct-an
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The categories of this paper are: math
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The categories of this paper are: nucl-th