Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Reversal of the lattice structure in SrCoOx epitaxial thin films studied
  by real-time optical spectroscopy and first-principles calculations   Using real-time spectroscopic ellipsometry, we directly observed a reversible
lattice and electronic structure evolution in SrCoOx (x = 2.5 - 3) epitaxial
thin films. Drastically different electronic ground states, which are extremely
susceptible to the oxygen content x, are found in the two topotactic phases,
i.e. the brownmillerite SrCoO2.5 and the perovskite SrCoO3. First principles
calculations confirmed substantial differences in the electronic structure,
including a metal-insulator transition, which originates from the modification
in the Co valence states and crystallographic structures. More interestingly,
the two phases can be reversibly controlled by changing the ambient pressure at
greatly reduced temperatures. Our finding provides an important pathway to
understanding the novel oxygen-content-dependent phase transition uniquely
found in multivalent transition metal oxides.

11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg