Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Monatomic Co, CoO$_2$, and CoO$_3$ Nanowires on Ir(100) and Pt(100)
  surfaces: Formation, Structure, and Energetics   In this study we investigate the structural and chemical changes of monatomic
CoO$_2$ chains grown self-organized on the Ir(100) surface [P. Ferstl et al.,
PRL 117, 2016, 046101] and on Pt(100) under reducing and oxidizing conditions.
By a combination of quantitative low-energy electron diffraction, scanning
tunnelling microscopy, and density functional theory we show that the cobalt
oxide wires are completely reduced by H$_2$ at temperatures above 320 K and a
3x1 ordered Ir$_2$Co or Pt$_2$Co surface alloy is formed. Depending on
temperature the surface alloy on Ir(100) is either hydrogen covered (T < 400 K)
or clean and eventually undergoes an irreversible order-disorder transition at
about 570 K. The Pt$_2$Co surface alloy disorders with the desorption of
hydrogen, whereby Co submerges into subsurface sites. Vice versa, applying
stronger oxidants than O$_2$ such as NO$_2$ leads to the formation of CoO3
chains on Ir(100) in a 3x1 superstructure. On Pt(100) such a CoO$_3$ phase
could not be prepared so far, which however, is due to the UHV conditions of
our experiments. As revealed by theory this phase will become stable in a
regime of higher pressure. In general, the structures can be reversibly
switched on both surfaces using the respective agents O$_2$, NO$_2$ and H$_2$.

10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol