X-ray study of betaine arsenate and deuterated betaine arsenate

• Tipo: Artigo em Revista Científica Internacional
• Data: 2000

Autores

Moreira, JA (Autor) Outra; Kiat, JM (Autor) Outra; Chaves, MR (Autor) FCUP; Almeida, A (Autor) FCUP; Klopperpieper, A (Autor) Outra

Revista

Título: Physica Status Solidi (A) Applied Research

Vol. 178

Páginas: 633-643

ISSN: 0031-8965

Editora: John Wiley & Sons

Indexação

ISI Web of Knowledge - 5 Citações

Scopus - 5 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia dos materiais

Outras Informações

ID Authenticus: P-001-0AS

Abstract (EN): Accurate X-ray measurements were performed in betaine arsenate (BA) and strongly deuterated betaine arsenate (DBA92) in the temperature range 300 to 80 K. The temperature dependence of the lattice parameters was studied and it provides a clear evidence for the existence of two phase transitions, one at 119 K and another one at 107 K. The symmetry of the low temperature phase of BA is P1n1. Nevertheless, our results are not conclusive about the symmetry of the antiferroelectric and ferroelectric phases in DBA92. The correlation lengths of the ordered phases in BA and DBA92 involve a limited number of unit cells, thus providing evidence for the existence of small polar clusters in these materials below T-c2.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 11