Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Heavy-Electron Behavior and Structural Change in Ca1.7Sr0.3RuO4   Sr$_2$RuO$_4$ is an unconventional superconductor with a tetragonal
structure, whereas Ca$_2$RuO$_4$ is a Mott insulator with orthorhombic
symmetry. The substituted Ca$_{2-x}$Sr$_x$RuO$_4$ has yielded a rich phase
diagram that is just beginning to be explored in detail. Experimental
investigation of the resistivity $\rho$, susceptibility $\chi$, specific heat
C$_p$, Hall coefficient R$_H$, and X-ray diffraction of
Ca$_{1.7}$Sr$_{0.3}$RuO$_4$ reveals a structural phase transition near T$_0$ =
190 K and heavy-Fermion (HF) behavior below a coherence temperature T$^*$
$\sim$ 10 K, resembling that of the $\it{f}$-electron HF compound UPt$_3$. The
observation of T$^2$-dependence of $\rho$ below $\sim$ 0.5 K suggests a
Fermi-liquid ground state. Based upon our data and theoretical calculations, we
argue that the structural change at T$_0$ may be responsible for the formation
of the HF state.

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The categories of this paper are: hep-ex
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The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
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The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
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The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
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The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int