Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Structure, friction, and Raman spectroscopy of Re-doped bulk MoS$_2$
  from first principles   Doping MoS$_2$ with Re is known to alter the electronic, structural, and
tribological properties. Re-doped MoS$_2$ has been mainly studied in monolayer
or few-layer form, but can also be relevant for applications in many-layer or
bulk form. In this work, we use density functional theory to explore the phase
stability, Raman spectra, and atomic force microscopy (AFM) sliding
interactions of bulk Re-doped MoS$_2$. We consider the possibility of the Re
dopant existing at different locations and provide experimentally
distinguishable characteristics of the most likely sites -- Mo-substitution and
tetrahedral (t-) intercalation. We demonstrate and benchmark an approach to
calculate Raman spectra of doped materials with metallic densities of states by
using atomic Raman tensors from the pristine material. Applying this method to
the metallic Re-doped structures, we find consistent shifts in the Raman-active
peaks depending on Re dopant position: redshifts in both $A_{\rm 1g}$ and
$E_{2g}^1$ peaks in the t-intercalated case versus a redshift for $A_{\rm 1g}$
and blueshift for $E_{\rm 2g}^1$ peaks in the Mo-substituted case. AFM friction
forces, if the MoS$_2$ surface remains flat and unpuckered, are increased by Re
dopants, similar for Mo-substitution and t-intercalation, and would decrease
with the number of layers.

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The categories of this paper are: supr-con
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
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The categories of this paper are: adap-org
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
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The categories of this paper are: solv-int
3
The categories of this paper are: physics
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The categories of this paper are: comp-gas
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The categories of this paper are: math-ph
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The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
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The categories of this paper are: nlin
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The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga