Anomaly in the electric resistivity of one-dimensional uneven peanut-shaped C_(60) polymer film at a low temperature

摘要

We performed in situ four-probe measurements of the current-voltage characteristics of one-dimensional (1D) uneven peanut-shaped C_(60) polymer films in the temperature range 30-350K under ultrahigh vacuum conditions (2 × 10~(-7)Pa). Arrhenius plots of the film resistance with respect to temperature showed two different electron-conduction mechanisms. While electrons are conducted via a thermal excitation hopping at temperatures above 160K, the resistivity of the 1D polymer film exhibits an anomalous behavior that becomes fluctuated at a given value in the temperature range 40-90 K and decreases at temperatures below 40 K.