EPR studies of mixed-conductive glasses in the AgI–Ag2O–V2O5–P2O5 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 (Ag2O) to network former (V2O5–P2O5) 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 V4+OV5+ 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 3d1 electron and 51V nucleus, were determined and a local order around vanadium ions was proposed.