Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetic anisotropy energy of disordered tetragonal Fe-Co systems from
  ab initio alloy theory   We present results of systematic fully relativistic first-principles
calculations of the uniaxial magnetic anisotropy energy (MAE) of a disordered
and partially ordered tetragonal Fe-Co alloy using the coherent potential
approximation (CPA). This alloy has recently become a promising system for thin
ferromagnetic films with a perpendicular magnetic anisotropy. We find that
existing theoretical approaches to homogeneous random bulk Fe-Co alloys, based
on a simple virtual crystal approximation (VCA), overestimate the maximum MAE
values obtained in the CPA by a factor of four. This pronounced difference is
ascribed to the strong disorder in the minority spin channel of real alloys,
which is neglected in the VCA and which leads to a broadening of the d-like
eigenstates at the Fermi energy and to the reduction of the MAE. The ordered
Fe-Co alloys with a maximum L1_0-like atomic long-range order can exhibit high
values of the MAE, which, however, get dramatically reduced by small
perturbations of the perfect order.

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The categories of this paper are: stat
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
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The categories of this paper are: nlin
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The categories of this paper are: q-fin
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th