Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cation-ordered A$'_{1/2}$A$''_{1/2}$B$_2$X$_4$ magnetic spinels as
  magnetoelectrics   We show that 1:1 ordering of A$'$ and A$''$ cations in
A$'_{1/2}$A$''_{1/2}$B$_2$X$_4$ magnetic spinels results in appearance of
magnetoelectric properties. Possible value of magnetically induced electric
polarization is calculated using the recently proposed microscopic model, which
takes into account spin-dependent electric dipole moments of magnetic ions
located in noncentrosymmetric crystallographic positions. We build
phenomenological models of magnetic phase transitions in cation-ordered
spinels, which describe ferromagnetic and antiferromagnetic ordering patterns
of B cation spins, and calculate the respective magnetoelectric responses. We
find that magnetoelectric coefficients diverge at ferromagnetic or weak
ferromagnetic phase transitions in ordered spinels.

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The categories of this paper are: supr-con
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The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ