The linear and nonlinear impedance spectra of oxide glasses were measured in the frequency range of 1 mHz to 1 MHz and in the temperature range of 153K to 483K. Two groups of iron oxide glass samples were prepared, the first one containing alkaline ions and the second one without alkali. In the first group, compositions of glasses were as follows: (in %mol) 50% SiO2 , 25% PbO, 15% Fe2O3 and 15% one of alkaline oxides: Na2O, K2O, Li2O. These transition metal oxide glasses containing alkali should show mixed polaronic-ionic conductivity. However, two relaxation processes were observed only in glass doped with K2O. All samples of this group show no detectable nonlinearities in impedance spectra. In the second group, the content of iron ions are respectively 15%, 20% and 25%. These glasses are polaronic conductors and only one relaxation process was observed in them. In parallel, the contents of the third harmonics at certain samples achieves values ranging from 3% to 5% at temperature below 273K and low frequency region (1mHz).
Authors
Additional information
- Category
- Publikacja monograficzna
- Type
- rozdział, artykuł w książce - dziele zbiorowym /podręczniku w języku o zasięgu międzynarodowym
- Language
- angielski
- Publication year
- 2012
