Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Growth and properties of strained VOx thin films with controlled
  stoichiometry   We have succeeded in growing epitaxial films of rocksalt VOx on MgO(001)
substrates. The oxygen content as a function of oxygen flux was determined
using 18O2-RBS and the vanadium valence using XAS. The upper and lower
stoichiometry limits found are similar to the ones known for bulk material
(0.8<x<1.3). From the RHEED oscillation period a large number of vacancies for
both vanadium and oxygen were deduced, i.e. ~16% for stoichiometric VO. These
numbers are, surprisingly, very similar to those for bulk material and
consequently quite strain-insensitive. XAS measurements reveal that the
vacancies give rise to strong low symmetry ligand fields to be present. The
electrical conductivity of the films is much lower than the conductivity of
bulk samples which we attribute to a decrease in the direct overlap between t2g
orbitals in the coherently strained layers. The temperature dependence of the
conductivity is consistent with a variable range hopping mechanism.

16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg