Extended x-ray absorption fine structure (EXAFS) measurements have been performed at the K edge of iodine in (AgI)(1-y)(Ag2MoO4)(y) glasses, with y = 0.25 and 0.33, as a function of temperature from 25 K to the glass transition temperature T-g similar or equal to 323 K. EXAFS monitors the short-range component of the I - Ag distance distribution. At 25 K, iodine coordinates to about four silver ions, at an average distance about 0.06 angstrom larger than in beta-AgI. As temperature increases, EXAFS monitors a progressive depletion of the short-range distribution, due to transitions of Ag ions into a long-range component. Coordination number and mean value of the short-range I - Ag distribution decrease while temperature is increasing. EXAFS results give information on the local modifications around iodine due to the ionic diffusivity.
Influence of temperature on the local structure around iodine in fast-ion-conducting Agl : Ag2MoO(4) glasses
Rocca, Francesco;
2007
Abstract
Extended x-ray absorption fine structure (EXAFS) measurements have been performed at the K edge of iodine in (AgI)(1-y)(Ag2MoO4)(y) glasses, with y = 0.25 and 0.33, as a function of temperature from 25 K to the glass transition temperature T-g similar or equal to 323 K. EXAFS monitors the short-range component of the I - Ag distance distribution. At 25 K, iodine coordinates to about four silver ions, at an average distance about 0.06 angstrom larger than in beta-AgI. As temperature increases, EXAFS monitors a progressive depletion of the short-range distribution, due to transitions of Ag ions into a long-range component. Coordination number and mean value of the short-range I - Ag distribution decrease while temperature is increasing. EXAFS results give information on the local modifications around iodine due to the ionic diffusivity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
