Premium
Disorder and Dynamics in Pollucite from 133 Cs and 27 Al NMR
Author(s) -
Ashbrook Sharon E.,
Whittle Karl R.,
Le Pollès Laurent,
Farnan Ian
Publication year - 2005
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2005.00294.x
Subject(s) - leucite , tetragonal crystal system , ion , crystallography , materials science , chemistry , analytical chemistry (journal) , ceramic , crystal structure , organic chemistry , chromatography , composite material
Pollucite, CsAlSi 2 O 6 , a Cs polymorph of leucite (KAlSi 2 O 6 ), has been proposed for ceramic immobilization of 135 Cs and 137 Cs fission products. 133 Cs NMR of both low‐ (tetragonal) and high‐temperature (cubic) forms of pollucite exhibit a considerable distribution of local Cs environments. 29 Si and 27 Al NMR data from directly prepared pollucite show greater Al/Si disorder than either leucite, or pollucite produced by ion exchange. Little evidence for Cs motion is observed in tetragonal or cubic pollucite, and only at high temperatures (∼850°C) is any substantial dynamic behavior detected. Dynamic NMR lineshape calculations allow a determination of the frequency of Cs motion and diffusivity.