Relaxation dynamics of Ag4Te3O8 glass nanocomposites embedded with Ag2S nanoparticles

Stable beta-Ag2S nanocrystals were dispersed in the Ag4Te3O8 glass network. These beta-Ag2S nanocrystals modified the tellurite network by rupturing the Te-O-Te linkages in the tellurite matrix. This structural modification was found to be different from that of the AgI doped silver tellurite glasses. The presence of beta-Ag2S nanoparticles was confirmed from the transmission electron micrographs. The structural modification was observed in the Fourier transform infrared spectra of the composites. Electrical properties for these composites were investigated in the temperature range of 125-303 K and in the frequency range of 10 Hz-2 MHz and were compared with those of the AgI doped silver tellurite glass system to shed some light on the influence of Ag2S nanoparticles on the ionic conduction and relaxation in the silver tellurite nanocomposites. The ionic relaxation in this system was also investigated using the electrical modulus formalism. Formation of nanocrystal in this nanocomposite system left some signature on the frequency exponent, crossover frequency, and the relaxation frequency, which became clear when compared with those of the silver tellurite glasses. (c) 2007 American Institute of Physics.