Open AccessEXAFS study of glass transition in K 1– x (NH 4 ) x I
Author(s) -
Yagi Kenichiro,
Sakaue Kiyoshi,
Terauchi Hikaru
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/s0909049500018331
Subject(s) - extended x ray absorption fine structure , ion , antiferroelectricity , iodine , ammonium , lattice (music) , local structure , chemistry , analytical chemistry (journal) , crystallography , materials science , absorption spectroscopy , physics , optics , dielectric , ferroelectricity , optoelectronics , organic chemistry , chromatography , acoustics
The iodine K ‐edge EXAFS study of K 1− x (NH 4 ) x I mixed crystals was performed to clarify the local structure of the dipole glass associated with the random reorientational freezing of ammonium ions. The pair‐distribution function of the nearest iodine‐iodine ions is strongly reduced with increasing ammonium concentration. The reduction originates in the local distortion of lattice induced by the short‐range antiferroelectric order of ammonium ions. We discuss the relationship between the reorientational freezing of ammonium ions and the local distortion of lattice in comparison with the results of X‐ray diffraction measurements.