EPR studies of mixed-conductive glasses in the AgI-Ag sub(2)O-V sub(2)O sub(5)-P sub(2 )O sub(5) system

Three families of mixed conductive silver-vanadate-phosphate glasses have been studied by electron paramagnetic resonance (EPR) spectroscopy. The EPR spectra are sensitive to glass modifier (Ag sub(2)O) to network former (V sub(2)O sub(5)-P sub(2)O sub(5)) ratio r. For r values close to 1, the hyperfine structure (hfs) of the EPR bands is observed. The presence of a hfs is an indicator of the glass network disruption. Therefore, its absence may indirectly point on enhanced electron hopping between aliovalent vanadium centers along V super(4+ )-O-V super(5+) bonds. A method was proposed to extract hfs from apparently unresolved EPR spectra. Using a simulation procedure the parameters of a Hamiltonian responsible for interaction between spins of 3d super(1) electron and super(51)V nucleus, were determined and a local order around vanadium ions was proposed. copyright 2001 Elsevier Science B.V.