Abstract
A series of glass samples has been prepared from mixtures of Na
2
B
4
O
7
, and Fe
2
O
3
. Measurements have been made of the d.c. conductivity as a function of temperature and composition. These results have been interpreted in terms of the activation energy, which increased with a small addition of Fe
2
O
3
(0.5 mol.%) in Na
2
B
4
O
7
glasses but decreased again with further addition of Fe
2
O
3
. D.c. conductivity measurements have revealed a mixed conduction phenomenon in which ionic as well as electronic conduction occur in the glass. Differential scanning calorimetry (DSC) as a function of Fe
2
O
3
content is also measured.