Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Stabilizing Single Ni adatoms on a Two-dimensional Porous Titania
  Overlayer at the SrTiO$_3$(110) Surface   Nickel vapor-deposited on the SrTiO$_3$(110) surface was studied using
scanning tunneling microscopy, photoemission spectroscopy (PES), and density
functional theory calculations. This surface forms a (4 $\times$ 1)
reconstruction, composed of a 2-D titania structure with periodic six- and
ten-membered nanopores. Anchored at these nanopores, Ni single adatoms are
stabilized at room temperature. PES measurements show that the Ni adatoms
create an in-gap state located at 1.9 eV below the conduction band minimum and
induce an upward band bending. Both experimental and theoretical results
suggest that Ni adatoms are positively charged. Our study produces
well-dispersed single-adatom arrays on a well-characterized oxide support,
providing a model system to investigate single-adatom catalytic and magnetic
properties.

37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex