Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Surface structures of tellurium on Si(111)-(7x7) studied by low-energy
  electron diffraction and scanning tunneling microscopy   The Te-covered Si(111) surface has received recent interest as a template for
the epitaxy of van der Waals (vdW) materials, e.g. Bi$_2$Te$_3$. Here, we
report the formation of a Te buffer layer on Si(111)$-$(7$\times$7) by
low-energy electron diffraction (LEED) and scanning tunneling microscopy (STM).
While deposition of several monolayer (ML) of Te on the Si(111)$-$(7$\times$7)
surface at room temperature results in an amorphous Te layer, increasing the
substrate temperature to $770\rm\,K$ results in a weak (7$\times$7) electron
diffraction pattern. Scanning tunneling microscopy of this surface shows
remaining corner holes from the Si(111)$-$(7$\times$7) surface reconstruction
and clusters in the faulted and unfaulted halves of the (7$\times$7) unit
cells. Increasing the substrate temperature further to $920\rm\,K$ leads to a
Te/Si(111)$-(2\sqrt3\times2\sqrt{3})\rm R30^{\circ}$ surface reconstruction. We
find that this surface configuration has an atomically flat structure with
threefold symmetry.

22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas