Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Soft antiphase tilt of oxygen octahedra in the hybrid improper
  multiferroic Ca3Mn1.9Ti0.1O7   We report a single crystal neutron and x-ray diffraction study of the hybrid
improper multiferroic Ca3Mn1.9Ti0.1O7 (CMTO), a prototypical system where the
electric polarization arises from the condensation of two lattice distortion
modes.With increasing temperature (T ), the out-of-plane, antiphase tilt of
MnO6 decreases in amplitude while the in-plane, in-phase rotation remains
robust and experiences abrupt changes across the first-order structural
transition. Application of hydrostatic pressure (P) to CMTO at room temperature
shows a similar effect. The consistent behavior under both T and P reveals the
softness of antiphase tilt and highlights the role of the partially occupied d
orbital of the transition-metal ions in determining the stability of the
octahedral distortion. Polarized neutron analysis indicates the
symmetry-allowed canted ferromagnetic moment is less than the 0.04 {\mu}B/Mn
site, despite a substantial out-of-plane tilt of the MnO6 octahedra.

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The categories of this paper are: cmp-lg
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The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
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The categories of this paper are: eess
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga