Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Initial stages of nickel oxide growth on Ag(001) by pulsed laser
  deposition   Submonolayers of nickel oxide films were grown on an Ag(001) by pulsed laser
deposition, and characterized in-situ by both scanning tunneling microscopy and
X-ray photoelectron spectroscopy. We observed quasi-two-dimensional growth of
the film, and clearly identified several kinds of defects, such as embedded
metallic Ni clusters and, notably, oxygen atoms, even while looking deeply into
the substrate. These originated from Ni and O hyperthermal projectiles as well
as from NiO clusters that were formed during laser ablation of a NiO target.
Those defects played a role of nucleation sites in extending the nucleation
stage of thin film growth.

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The categories of this paper are: quant-ph
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The categories of this paper are: stat
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph