Open AccessEXAFS study of phase transitions in KIO 3
Author(s) -
Yagi Kenichiro,
Umezawa Shunsuke,
Terauchi Hikaru,
Kasatani Hirofumi
Publication year - 2001
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s090904950001832x
Subject(s) - extended x ray absorption fine structure , ionic bonding , covalent bond , debye–waller factor , octahedron , bond length , chemistry , phase transition , phase (matter) , oxygen , k edge , molecule , crystallography , chemical physics , ion , absorption spectroscopy , condensed matter physics , crystal structure , physics , optics , organic chemistry , diffraction
The iodine K ‐edge EXAFS study of KIO 3 $ was performed to clarify local structural changes on the successive phase transitions. The pair‐distribution function of three oxygen atoms in an oxygen octahedron is almost independent on temperature like a covalent bond, whereas that of the other three is gradually reduced with increasing temperature like an ionic bond. The result indicates that iodine and oxygen atoms exist as an IO 3 − molecule in a pseudo‐perovskite‐type structure. The anomalous behavior in the Debye‐Waller factor for the latter pair‐distribution function appears around 50 K, which is associated with the orientational glass transition.