Abstract
The electrical conductivity of a series of glass samples in the system GeO
2
-PrCI
3
was measured as a function of temperature and composition. The activation energy decreased with a small addition of PrCl
3
(1 mol.%) in GeO
2
glasses but increased again for further addition of PrCI
3
. Voltage-current characteristics at low electric field showed ohmic behaviour at different temperatures. Differential scanning calorimetry (DSC) gave no indication of structural transitions in the temperature range 303-873 K.