Abstract
Glass of composition 10PbTiO
3
–60V
2
O
5
–30B
2
O
3
in mol% was prepared by conventional melt quenching technique. Annealing process was applied to the glass samples at temperature close to crystallization temperature T
c
for different time intervals 1, 2, 4, 8 and 24 h, respectively to obtain glass ceramic nano-composites. The samples densities were measured by Archimedes method. Differential scanning calorimeter data confirms the amorphous nature and shows high homogeneity of the glass sample. Transmission electron microscopy and X-ray diffraction were also used to confirm the amorphous nature and the existence of nano crystallites embedded in the glass matrix. Glass ceramic nano-composites show giant enhancement in electrical conductivity (about 6 orders of magnitude) as a function of heat treatment times. This enhancement of conductivity is attributed to the increase in crystal size which leads to the increase in the concentration of V ions pairs and the reduction of grain boundary scattering effect. The dc electrical conductivity in the present glass and corresponding glass ceramic nano-composites at high temperature T > (θ
D
/2), (θ
D
: Deby temperature) was due to non-adiabatic small polaron hopping of electron between vanadium ions.