The local environment around iodine has been studied as a function or temperature by extended X-ray absorption fine structure (EXAFS) in fast-ion-conducting AgI doped glasses (borate and molybdate): silver borate glass (AgI)(0.55)(Ag2O:4 center dot B2O3)(0.45) has been investigated front 39 to 298 K, and silver molybdate glasses (AgI)(x)(Ag2MoO4)(1-x), with x=.67 and x = 0.75, from 25 K to T-g (330-350 K). In spite of the very different character of their host matrices, these two families of glasses display a very similar local thermal behaviour around iodine: the mean distance and the coordination number of the short-range I-Ag distrubution decrease when the temperature increases. These experimental results can be related to the temperature dependence of the diffusion of the silver ions, giving new elements to better understand the mechanism of ionic conduction.
Thermal behaviour of the local environment around iodine in fast-ion-conducting AgI-doped glasses
Rocca, Francesco;
2007-01-01
Abstract
The local environment around iodine has been studied as a function or temperature by extended X-ray absorption fine structure (EXAFS) in fast-ion-conducting AgI doped glasses (borate and molybdate): silver borate glass (AgI)(0.55)(Ag2O:4 center dot B2O3)(0.45) has been investigated front 39 to 298 K, and silver molybdate glasses (AgI)(x)(Ag2MoO4)(1-x), with x=.67 and x = 0.75, from 25 K to T-g (330-350 K). In spite of the very different character of their host matrices, these two families of glasses display a very similar local thermal behaviour around iodine: the mean distance and the coordination number of the short-range I-Ag distrubution decrease when the temperature increases. These experimental results can be related to the temperature dependence of the diffusion of the silver ions, giving new elements to better understand the mechanism of ionic conduction.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
