ELECTRONIC TRANSPORT IN RUO2-BASED THICK-FILM RESISTORS AT LOW-TEMPERATURES

The electrical conductivity of various RuO2-based thick film paste res istors was investigated in the temperature range between 50 mK and 20 K. It is shown that models based on variable range hopping and simple models based on tunnelling of charge carriers between conductive grain s do not provide a satisfactory explanation for the temperature depend ence of the electrical conductivity in these materials at very low tem peratures. We suggest a new mechanism based on tunnelling of electrons through graded barriers between conductive particles.