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Structural and transport properties of Li-intercalated vanadium pentoxide nanocrystalline films

M. S. Al-Assiri1,#, M. M. El-Desoky1,2 , A. Alyamani3, A. Al-Hajry1, A. Al-Mogeeth1, and A. A. Bahgat1
 

Abstract

 

X-ray diffraction (XRD), density, electrical and thermoelectric power properties of nanocrystalline LixV2O5, nH2O films (0 < x < 22 mol %) were investigated in the present work. These films have been produced by the sol-gel technique (colloidal route) which was used for preparation of high purity and uniform films at room temperature. The films were studied by x-ray diffraction  showed that, LixV2O5, nH2O films are highly orientated nanocrystals. The particle size was found to be about 6.0 nm. The relative intensity of the diffraction line (002) increases with increasing Li-content. Electrical conductivity and thermoelectric power were measured in the temperature range 300–480 K for the as prepared films parallel to the substrate surface; i.e. normal to the c-axis. The electrical conductivity on the other hand, shows that all samples are semiconductor and increases with increasing Li content. The hopping carrier mobility were also evaluated and found to vary from 6.81 ×10-6 to 0.33×10-6 cm-2 V-1 s-1 at T = 380 K. The carrier density is evaluated to be 0.873 x 1020 – 11.18 x 1020 cm-3. The conductivity of the present system was primarily determined by hopping carrier mobility. The conduction was confirmed to obey the non-adiabatic small polaron hopping. The thermoelectric power, Seebeck effect, increases with increasing the Li content. The obtained results showed an n-type semiconducting behavior within the whole temperature range.






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