An EXAFS study of AgPO3 and AgBaP3O9

The local structure around silver atoms in the crystalline and glassy forms of AgBaP3O9 and AgPO3 has been investigated using Extended X-ray Absorptio n Fine Structure Spectroscopy (EXAFS). The results are reported at the silv er K-edge. The structure of AgBaP3O9 is representative of isolated silver w hereas silver pairs have been evidenced in crystalline AgPO3. The present i nvestigation allows to detect the formation of Ag+-Ag+ pairs in both glasse s. These data are consistent with crystal chemistry of silver phosphates an d the luminescent properties of these materials.