Raman scattering study of the phase transition sequence in the (BA)(1-x)(DBA)(x) system

• Tipo: Artigo em Revista Científica Internacional
• Data: 1998

Autores

Moreira, JA (Autor) Outra; Almeida, A (Autor) FCUP; Chaves, MR (Autor) FCUP; Mota, MF (Autor) Outra; Klopperpieper, A (Autor) Outra; Pinto, F (Autor) Outra

Revista

Título: Journal of Physics Condensed Matter

Vol. 10

Páginas: 6825-6844

ISSN: 0953-8984

Editora: Institute of Physics Publishing

Indexação

ISI Web of Knowledge - 12 Citações

Scopus - 14 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Física

Outras Informações

ID Authenticus: P-001-7AN

DOI: 10.1088/0953-8984/10/30/020

Abstract (EN): We have measured the polarized Raman spectra of betaine arsenate and deuterated betaine arsenate single crystals in the temperature range 12-300 K. On the basis of the comparative study of Raman spectra of protonated and deuterated compounds and by taking into account the relevant literature data, we proposed a mode assignment for (BA)(1-x)(DBA)(x). The isotopic effect in this system is discussed. The analysis of the internal modes of AsO43- clearly shows the important role played by this unit in the phase sequence of (BA)(1-x)(DBA)(x). The strong coupling exhibited by the proton/deuteron modes with the internal modes of AsO43- provides some evidence for the ordering of the hydrogen bonds at the phase transitions. In DBA(92) this analysis reveals the existence of two types of hydrogen bond related to the mechanisms underlying the phase transitions.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 20