Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Giant electrocaloric effect around T$_c$   We use molecular dynamics with a first-principles-based shell model potential
to study the electrocaloric effect (ECE) in lithium niobate, LiNbO$_3$, and
find a giant electrocaloric effect along a line passing through the
ferroelectric transition. With applied electric field, a line of maximum ECE
passes through the zero field ferroelectric transition, continuing along a
Widom line at high temperatures with increasing field, and along the
instability that leads to homogeneous ferroelectric switching below $T_c$ with
an applied field antiparallel to the spontaneous polarization. This line is
defined as the minimum in the inverse capacitance under applied electric field.
We investigate the effects of pressure, temperature and applied electric field
on the ECE. The behavior we observe in LiNbO$_3$ should generally apply to
ferroelectrics; we therefore suggest that the operating temperature for
refrigeration and energy scavenging applications should be above the
ferroelectric transition region to obtain large electrocaloric response. We
find a relationship among $T_c$, the Widom line and homogeneous switching that
should be universal among ferroelectrics, relaxors, multiferroics, and the same
behavior should be found under applied magnetic fields in ferromagnets.

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The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math