Formation and Conductive Properties of Miniaturized Fullerite Sensors

摘要

Fullerite nanotubules of 100nm to 2 μm radius, up to 200nm wall thickness and 10 μm length were produced inside etched swift heavy ion tracks in a polymer, by letting fullerene precipitate from a concentrated C_(60) solution within the tracks. After contacting the tubules on both sides with silver paste, their resistivity was measured as a function of temperature. All of the 13 prepared samples show a complex behaviour that can be described by two Arrhenius curves, the low temperature branch with activation energy E_(act) = (1.77 +- 0.2)eV stemming from pure C_(60), and the high temperature branch being tentatively ascribed to C_(60)Ag_x with x ≈ 12.4 and Eact = (0.68 +- 0.2)eV, as the latter compound has found to be produced at ambient temperature by C_(60) / Ag thermal intermixture. Such samples with two branches of negative temperature coefficients of resistance might be useful to construct advanced thermoresistors.