Non-adiabatic polaron hopping conduction in semiconducting V2O5-Bi2O3 oxide glasses doped with BaTiO3
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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, rp, 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.
KeywordsElectrical Conductivity BaTiO3 V2O5 Decay Constant Glass Sample
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- 2.C. H. Chung, J. D. Mackenzie and L. Murawski, Rev. Chem. Miner. 16 (1979) 308.Google Scholar
- 5.H. Hirashima, Y. Watanabe and T. Yoshida, ibid. 95/96 (1987) 826.Google Scholar
- 8.A. Ghosh and B. K. Chaudhuri, in “Proceedings of the National Seminar on Semiconductor and Devices”, Calcutta (1986) p. 28.Google Scholar
- 14.R. Wernickle, in “Grain boundary phenomena in Electronic ceramics”, Vol. I, Edited by L. H. Leison (American Ceramic Society) Westerville, OH, 1981) p. 261.Google Scholar
- 18.Y. Kawamoto, M. Fukuzuko, Y. Ohta and M. Imai, Phys. Chem. Glasses 20 (1979) 54.Google Scholar
- 19.S. Chakraborty, S. Sadhukhan, K. K. Som, H. S. Maiti and B. K. Chaudhuri, Phil. Mag. B (1995) in press.Google Scholar
- 25.I. G. Austin and E. S. Garbett, in “Electronic and structural properties of amorphous semiconductors”, edited by P. G. Lecomber and J. Mort (Academic Press, London, New York) p. 393.Google Scholar
- 28.V. N. Bogomolov, E. K. Kudinev and U. N. Firsov, Sov. Phys. Solid State 9 (1968) 2502; (Fizika Tverodogo Tela. 9(1967) 3175).Google Scholar
- 31.N. F. Mott and E. A. Davis, in “Electronic processes in non-crystalline materials”, 2nd Ed (Clarendon, Oxford, 1979).Google Scholar