Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Room temperature exchange bias in BiFeO3 / Co-Fe bilayers   Thin highly epitaxial BiFeO$_3$ films were prepared on SrTiO$_3$ (100)
substrates by reactive magnetron co-sputtering. Detailed MOKE measurements on
BiFeO$_3$/Co-Fe bilayers were performed to investigate the exchange bias as a
function of the films thicknesses and Co-Fe stoichiometries. We found a maximum
exchange bias of H$_{\mathrm{eb}}$=92 Oe and a coercive field of
H$_{\mathrm{c}}$=89 Oe for a 12.5 nm thick BiFeO$_3$ film with a 2 nm thick Co
layer. The unidirectional anisotropy is clearly visible in in-plane rotational
MOKE measurements. AMR measurements reveal a strongly increasing coercivity
with decreasing temperature, but no significant change in the exchange bias
field.

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The categories of this paper are: nucl-ex
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The categories of this paper are: cs
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The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
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The categories of this paper are: chao-dyn
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
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The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: q-fin
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The categories of this paper are: econ
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The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
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The categories of this paper are: math-ph