Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Polarization rotation and the electrocaloric effect in barium titanate   We study the electrocaloric effect in the classic ferroelectric BaTiO3
through a series of phase transitions driven by applied electric field and
temperature. We find both negative and positive electrocaloric effects, with
the negative electrocaloric effect, where temperature decreases with applied
field, in monoclinic phases. Macroscopic polarization rotation is evident
through the monoclinic and orthorhombic phases under applied field, and is
responsible for the negative electrocaloric effect.

19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an