ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract BaTiO3-doped (5–40 wt %) 90V2O5-10Bi2O3 (VB) glasses have been prepared by a quick quenching technique. The d.c. electrical conductivities, σd.c., of these glasses have been reported in the temperature range 80–450 K. The electrical conductivity of these glasses, which arises due to the presence of V4+ and V5+ ions, has been analysed in the light of the small-polaron hopping conduction mechanism. The adiabatic hopping conduction valid for the undoped VB glasses (with 80–95 mol % V2O5), in the high-temperature region, is changed to a non-adiabatic hopping mechanism in the BaTiO3-doped VB glasses. At lower temperatures, however, a variable range hopping (VRH) mechanism dominates the conduction mechanism in both the glass systems. Such a change-over from adiabatic to non-adiabatic conduction mechanism is a new feature in transition metal oxide glasses. Various parameters, such as density of states at the Fermi level N(EF), electron wave-function decay constant, α, polaron radius, r p, and its effective mass, m p * , etc., have been obtained for all the glass samples from a critical analysis of the electrical conductivity data satisfying the theory of polaron hopping conduction.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00356061
Permalink