The glassy and glassy-crystalline materials of nominal composition xAgI.(100-x) (0.75Ag(2)O center dot 0.25P(2)O(5)), for 50 <= x <= 85, were investigated by DSC and XRD methods. For a composition corresponding to x = 50 an additional series of DSC scans at different heating rates from 6 to 20 K.min(-1) was carried out. These measurements revealed the occurrence of three crystallization processes. The systematic shifts of their characteristic temperatures, depending on the heating rates were analyzed using the Kissinger approach. Activation energies of these processes were determined. Their values are 179 kJ/mol, 156 kJ/mol and 169 kJ/mol, respectively. (c) 2007 Elsevier B.V All rights reserved.