Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Frustrated three-dimensional antiferromagnet Li$_{2}$CuW$_{2}$O$_{8}$:
  $^7$Li NMR and the effect of non-magnetic dilution   We report a $^7$Li nuclear magnetic resonance (NMR) study of a frustrated
three-dimensional \mbox{spin-$\frac12$} antiferromagnet
Li$_{2}$CuW$_{2}$O$_{8}$ and also explore the effect of non-magnetic dilution.
The magnetic long-range ordering in the parent compound at $T_{\rm N}\simeq$
3.9~K was detected from the drastic line broadening and a peak in the
spin-lattice relaxation rate ($1/T_1$). The NMR spectrum above $T_{\rm N}$
broadens systematically, and its full width at half maximum (FWHM) tracks the
static spin susceptibility. From the analysis of FWHM vs. static
susceptibility, the coupling between the Li nuclei and Cu$^{2+}$ ions was found
to be purely dipolar in nature. The magnitude of the maximum exchange coupling
constant is $J_{\rm max}/k_{\rm B}\simeq 13$\,K. NMR spectra below $T_{\rm N}$
broaden abruptly and transform into a double-horn pattern reflecting the
commensurate nature of the spin structure in the ordered state. Below $T_{\rm
N}$, 1/$T_1$ follows a $T^5$ behavior. The frustrated nature of the compound is
confirmed by persistent magnetic correlations at high temperatures well above
$T_{\rm N}$. The dilution of the spin lattice with non-magnetic Zn atoms has
dramatic influence on $T_N$ that decreases exponentially similar to
quasi-one-dimensional antiferromagnets, even though Li$_2$CuW$_2$O$_8$ has only
a weak one-dimensional anisotropy. Heat capacity of doped samples follows power
law ($C_{\rm p} \propto T^{\alpha}$) below $T_{\rm N}$, and the exponent
($\alpha$) decreases from 3 in the parent compound to 1 in the 25\% doped
sample.

7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org