Structure determination of AgPO3 and (AgPO3)0.5(AgI)0.5 glasses by neutron diffraction and small angle neutron scattering
Abstract Neutron diffraction and small angle neutron scattering (SANS) were performed on AgPO 3 and (AgPO 3 ) 0.5 (AgI) 0.5 glasses. AgPO 3 glass is made up of long chains of PO 4 tetrahedra joined together by Ag atoms. When silver iodide is added, the radial distribution function shows a large peak at 2.83 A, due to AgI interactions. AgI does not modify the network forming unit. The existence of small clusters is confirmed by analysing the coordination number of AgI pairs obtained by subtracting the experimental structure function of the AgPO 3 glass from that of the corresponding AgI-doped glasses. A rough estimation of their size is given by SANS experiments. Not all the AgI pairs are involved in AgI cluster units. The compatibility of the results obtained with recent structural investigations by non diffractometric techniques is examined.