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Crystal Structure of the Ferroelectric Phase of (BP) 0.08 (BPI) 0.92
Author(s) -
Andrade L. C. R.,
Santos M. L.,
Silvestre J.,
Costa M. M. R.,
Chaves M. R.,
Almeida A.,
Klöpperpieper A.
Publication year - 1999
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/(sici)1521-3951(199910)215:2<975::aid-pssb975>3.0.co;2-q
Subject(s) - ferroelectricity , phase (matter) , materials science , crystallography , crystal structure , chemistry , optoelectronics , organic chemistry , dielectric
We have determined the structure of (BP) 0.08 (BPI) 0.92 both in the ferrodistortive (at ≈294 K) and in the ferroelectric (at ≈146 K) phases, by single crystal X‐ray diffraction measurements. A detailed comparison between the structures revealed small but significant structural distortions, consisting almost exclusively of rotations which evidence the order–disorder nature of protons in the bonds linking neighbouring molecules in the chains and confirm the increase of the hybridization of the orbitals of the O–H valence electrons in these bonds upon cooling. These observations suggest that the proton ordering may be, if not the only contribution to the macroscopic polarization, at least the mechanism triggering the para–ferroelectric phase transition in (BP) 0.08 (BPI) 0.92 .