Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: p-Type Zinc Oxide Spinels: Application to Transparent Conductors and
  Spintronics   We report on the electronic and optical properties of two theoretically
predicted stable spinel compounds of the form ZnB2O4, where B = Ni or Cu;
neither compound has been previously synthesized, so we compare them to the
previously studied p-type ZnCo2O4 spinel. These new materials exhibit spin
polarization that is ideal for spintronics applications, and broad conductivity
maxima near the valence band edge that facilitate p-type dopability. We show
that 3d electrons on the octahedrally coordinated Zn atom fall deep within the
valence band and do not contribute significantly to the electronic structure of
the material, while the O 2p and tetrahedrally coordinated B 3d electrons
hybridize broadly in the shallow valence states, resulting in increasing
curvature (i.e., decreased electron effective mass) of valence bands near the
band edge. In particular, ZnCu2O4 exhibits high electrical conductivities near
the valence band edge that, at sigma = 2 x 10^4 S/cm, are twice the maximum
found for ZnCo2O4, a previously synthesized compound in this class of
materials. This material also exhibits ferromagnetism in all of its most stable
structures, which makes it a good candidate for further study as a dilute
magnetic semiconductor.

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The categories of this paper are: stat
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
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The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
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The categories of this paper are: econ
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
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The categories of this paper are: q-alg
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The categories of this paper are: cmp-lg