Electrical transport and AFM microscopy on V2O5-x-polyaniline nanorods

With the aim of obtaining nanodevices as rectifiers or transistors, we obta ined (V2O5-x-polyaniline) nanorods, as it has been previously described, wh ere the polymerisation of aniline is favoured by reduction of V2O5. We meas ured the I(V) characteristics and electrical resistance in the temperature range from RT to 140 K, on nanorods ( < 20-nm thick and 300-800-nm long) de posited on a sample holder, where six inter-digitated metallic contacts wer e previously made by lithography. Using AFM microscopy in tapping mode, we examined the samples and selected some that contacted either two or four wi res. In both cases, the I(V) characteristics were clearly nonlinear and sym metrical with respect to both axes. Electrical conductivity values at RT ar e near 10(-1) (S/cm). After that, a rectifying effect could be obtained if we were able to displace the characteristics on the axis. When the temperat ure was lowered below 140 K, electrical resistivity increased abruptly. (C) 2001 Elsevier Science BN. All rights reserved.