Resistivity, magnetoresistance and thermopower of zinc nanowire composites
Abstract
We reported last year [1] a very large increase of the thermoelectric power of 9 and 15 nm diameter nanowires of bismuth, compared to that of bulk bismuth. That effect was attributed to the effects of size-quantization on the electron energy structure in bismuth. In order to rule out other effects, we report here data on zinc nanowires, which are not expected to display size-quantization effects. The temperature dependence of the resistance, magnetoresistance, and thermopower of composites consisting of Zn nanowires imbedded in porous silica, alumina and glass is reported here, with wire diameters of 15, 9 and 4 nm respectively. The electrical resistivity and magnetoresistance is characteristic of metallic behavior in the 15 nm wires, and of one-dimensional localization in the 9 and 4 nm wires. The thermopower for the 9 and 4 nm wires is unlike that of bulk Zn: it is negative, and quite large, -20 uV/K for the 9 nm and -130 uV/K for the 4 nm wires at 300 K. Both the values and the temperature dependence of the thermopower are what one would expect for a system near the metal/insulator transition. The magnitude is 1000 times smaller than that of bismuth nanowires. 1. J. P. Heremans et al., Phys. Rev. Lett. 88, 216801 (2002)
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2003
- Bibcode:
- 2003APS..MARH25010H