Electrical properties of PbO–Bi2O3–Ga2O3 glasses with addition of Ag2O and Sb2O3

Formation of Ag nanoparticles in the PbO–Bi2O3–Ga2O3 heavy metal oxide glasses modified by addition of Ag2O and Sb2O3 was monitored using electrical and optical measurements. Electrical measurements are suitable for this purpose as they are very sensitive to any changes in the arrangement of the material structure. The formed spherical silver nanoparticles were studied by a high-resolution transmission electron microscopy (HRTEM), their nature was confirmed by selected area electron diffraction analysis (SAED) and x-ray photoelectron spectroscopy (XPS). We demonstrated and documented that the samples containing Ag/Sb change during additional heating (in the investigated temperature range of 240–290 °C) – the electrical conductivity changes and also the relaxation time as established by electrical modulus measurements changes. The behaviour of the base glass without Ag/Sb addition remains practically unaffected by the same additional heating. TEM confirmed an increased number of spherical nanoparticles as a consequence of heat treatment. The indexes of the SAED pattern match the fcc-Ag crystalline phase, HRTEM identified the periodical arrangement in these particles to correspond to d-spacing of (111) planes in Ag and the elemental state of the present Ag in the heat-treated sample was confirmed also by XPS.