Please use this identifier to cite or link to this item: http://hdl.handle.net/1822/13943

TitleThe phase transition sequence of betaine arsenate investigated by infrared reflectivity
Author(s)Ribeiro, J. L.
Vieira, L. G.
Dekola, T.
Gomes, I. Tarroso
KeywordsPhase transitions
Infrared spectroscopy
Solid organic materials
Ferroelectric and antiferroelectric materials
Phonon–photon interaction
Infrared spectra
Issue date2009
JournalVibrational Spectroscopy
Abstract(s)The ac-polarized infrared reflectivity spectra of betaine ortho-arsenic acid single crystals have been measured throughout the ferroelastic–ferroelectric phase transition observed near Tc2 = 120 K. The monoclinic symmetry of the system was explicitly taken into account and a three-polarization technique used for the first time to investigate in detail the critical behaviour of the Bu polar phonons. The results show that near the THz frequency range, the usual approximation of considering the system as pseudoorthorhombic fails, giving rise to errors in the determination of the optical parameters. The obtained spectroscopic data indicate that the phase diagram and the physical mechanism involved in the stabilization of ferroelectricity in betaine arsenate (BA) are more complex than the prevalent view of a simple ordering process in bistable hydrogen bonds.
TypeArticle
URIhttp://hdl.handle.net/1822/13943
Peer-Reviewedyes
AccessRestricted access (UMinho)
Appears in Collections:CDF - FCD - Artigos/Papers (with refereeing)

Files in This Item:
File Description SizeFormat 
vibrational spectroscopy50_198(2009).pdf
  Restricted access
890,89 kBAdobe PDFView/Open

Partilhe no FacebookPartilhe no TwitterPartilhe no DeliciousPartilhe no LinkedInPartilhe no DiggAdicionar ao Google BookmarksPartilhe no MySpacePartilhe no Orkut
Exporte no formato BibTex mendeley Exporte no formato Endnote Adicione ao seu ORCID