X-ray study of betaine arsenate and deuterated betaine arsenate

• Type: Article in International Scientific Journal
• Date: 2000

Authors

Moreira, JA (Author) Other; Kiat, JM (Author) Other; Chaves, MR (Author) FCUP; Almeida, A (Author) FCUP; Klopperpieper, A (Author) Other

Journal

Title: Physica Status Solidi (A) Applied Research

Vol. 178

Pages: 633-643

ISSN: 0031-8965

Publisher: John Wiley & Sons

Indexing

ISI Web of Knowledge - 5 Citations

Scopus - 5 Citations

Scientific classification

FOS: Engineering and technology > Materials engineering

Other information

Authenticus ID: 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11