Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Experimental and Computational Studies of the Optical Properties of
  CuAl1-xFexO2   Delafossites are promising candidates for photocatalysis applications because
of their chemical stability and absorption in the solar region of the
electromagnetic spectrum. For example, CuAlO2 has good chemical stability but
has a large indirect bandgap (~3 eV), so that efforts to improve its absorption
in the solar region through alloying are investigated. The effect of dilute
alloying on the optical absorption of powdered CuAl1-xFexO2 (x = 0.0-1.0) is
measured and compared to electronic band structures calculations using a
generalized gradient approximation with Hubbard exchange-correlation parameter
and spin. A new absorption feature is observed at 1.8 eV for x = 0.01, which
redshifts to 1.4 eV for x = 0.10. This feature is associated with transitions
from the L-point valence band maximum to the Fe-3d state that appears below the
conduction band of the spin-down band structure. The feature increases the
optical absorption below the bandgap of pure CuAlO2, making dilute CuAl1-xFexO2
alloys better suited for solar photocatalysis.

26
The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
17
The categories of this paper are: q-fin