Abstract: The dc electrical transport properties of the quaternary glass
system are studied in the
temperature range from 120 to 500K. The density is measured and
the molar volume is calculated as well as the number of oxygen, vanadium and
zinc ion densities.
It is found that, as zinc oxide is gradually increased at the
expense of vanadium oxide, the dc electrical conductivity exhibits a gradual
decrease while the activation energy, the optical phonon frequency, the polaron
hopping distance and Debye temperature have shown approximately a gradual
increase. The small polaron hopping model is the supposed conduction mechanism
appearing in these glasses at high temperatures while at low
temperatures the variable range
hopping (VRH) mechanism is evidenced to take place.
Also, the density has shown a gradual linear increase
while the molar volume exhibits a linear decrease. The number of vanadium and
oxygen ion densities has shown a slight linear decrease while that of zinc has
shown a gradual increase, but the values of the vanadium ion spacing distances
have shown a gradual increase. All the obtained results are discussed on the
bases of the theories of the electrical conduction in amorphous solids.
Keywords and phrases: transition metal oxide glasses, unconventional oxide glasses, dc electrical properties of glasses at high and low temperatures.
