Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Trapping of Compensating Charges in Corona Poled PVDF Films   Experimental evidence is provided on close relation between polarization and
space charge in corona poled PVDF films. It is shown that the depolarizing
field is compensated by charges trapped in macroscopic transition zones, by
which polarized parts of the volume are separated from non-polarized ones. The
compensating charges are either injected in the bulk, or created inside due to
the thermal emission and then trapped when the ferroelectric polarization in
crystallites is formed.

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The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas