Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: 180 degree Ferroelectric Stripe Nanodomains in BiFeO3 Thin Films   There is growing evidence that domain walls in ferroics can possess emergent
properties that are absent in bulk materials. For example, 180 domain walls in
the ferroelectric-antiferromagnetic BiFeO3 are particularly interesting because
they have been predicted to possess a range of intriguing behaviors; including
electronic conduction and enhanced magnetization. To date, however, ordered
arrays of such domain structures have not been reported. Here, we report the
observation of 180 stripe nanodomains in (110)-oriented BiFeO3 thin films grown
on orthorhombic GdScO3 (010)O substrates, and their impact on exchange coupling
to metallic ferromagnets. Nanoscale ferroelectric 180 stripe domains with {112
} domain walls were observed in films < 32 nm thick to compensate for large
depolarization fields. With increasing film thickness, we observe a domain
structure crossover from the depolarization field-driven 180 stripe nanodomains
to 71 domains determined by the elastic energy. Interestingly, these 180 domain
walls (which are typically cylindrical or meandering in nature due to a lack of
strong anisotropy associated with the energy of such walls) are found to be
highly-ordered. Additional studies of Co0.9Fe0.1/BiFeO3 heterostructures reveal
exchange bias and exchange enhancement in heterostructures based-on BiFeO3 with
180 domain walls and an absence of exchange bias in heterostructures based-on
BiFeO3 with 71 domain walls; suggesting that the 180 domain walls could be the
possible source for pinned uncompensated spins that give rise to exchange bias.
This is further confirmed by X-ray circular magnetic dichroism studies, which
demonstrate that films with predominantly 180 domain walls have larger
magnetization than those with primarily 71 domain walls. Our results could be
useful to extract the structure of domain walls and to explore domain wall
functionalities in BiFeO3.

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The categories of this paper are: physics
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The categories of this paper are: funct-an
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The categories of this paper are: nlin
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The categories of this paper are: comp-gas
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The categories of this paper are: gr-qc
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The categories of this paper are: eess
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The categories of this paper are: q-fin
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The categories of this paper are: math
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The categories of this paper are: stat
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The categories of this paper are: dg-ga
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-th
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The categories of this paper are: q-alg
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The categories of this paper are: mtrl-th
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The categories of this paper are: acc-phys
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The categories of this paper are: quant-ph