The neutron resonance absorption experiments were performed on an ionic con
ductor AgI and a reference sample Ag-metal, and the effective temperatures
were obtained in a wide temperature range of 20-300 K. The obtained effecti
ve temperatures in Ag-metal agree well with the calculated values from its
characteristic Debye temperature of theta(D) = 225 K. In AgI an anomaly is
found around 150 K where the Debye temperature of Ag-atom changes from thet
a(D) = 160 to 440 K, while nothing can be seen in that of I-atom. (C) 1999
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