STABLE AND X-RAY-INDUCED COMMENSURATE AND INCOMMENSURATE PHASES IN BETAINE CALCIUM-CHLORIDE DIHYDRATE

• Type: Article in International Scientific Journal
• Date: 1995

Authors

KIAT, JM (Author) Other; CALVARIN, G (Author) Other; Chaves, MR (Author) FCUP; Almeida, A (Author) FCUP; KLOPPERPIEPER, A (Author) Other; ALBERS, J (Author) Other

Journal

Title: Physical Review B

Vol. 52

Pages: 798-802

ISSN: 2469-9950

Publisher: American Physical Society

Indexing

ISI Web of Knowledge - 8 Citations

Scopus - 7 Citations

Other information

Authenticus ID: P-001-GQG

DOI: 10.1103/physrevb.52.798

Abstract (EN): We report a high-resolution x-ray-diffraction study of commensurate and incommensurate phases of betaine calcium chloride dihydrate [(CH3)(3)NCH2COO . CaCl2 . 2H(2)O or (BCCD)] above 80 K. Our results show that very strong pinning of the modulation can be induced due to x-ray irradiation, similar to the way it has been reported in some incommensurate organic compounds such as thiourea or TMATC-Co (N(CH3)4)(2)CoCl4. Using a procedure of direct cooling in order to avoid these pinnings, some results regarding the intrinsic behavior of the modulation and lattice parameters are given. in particular, direct evidence of the 3/11 and 4/15 commensurate phases is observed. In the corresponding temperature range, the modulation wave-vector evolution is characterized by a sequence of direct passages (first order) from 3/11 to 4/15 and then to 1/4, with coexistence of these phases in large temperature ranges.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5