Electrical resistivity of graphite is presented in the temperature range 900-2800K. In an atmosphere of nitrogen, electrical resistivity of isotropic graphite IG-110 increases with an increase in temperature. On the other hand, the temperature dependence of electrical resistivity in an atmosphere of argon is different: a significant decrease of electrical resistivity was observed above ca. 2400K. It was suggested that argon was not inert at temperatures above about 2400K, and affected the resistivity of graphite through some ionization or other reactions.
This atmosphere dependence of the electrical resistivity at elevated temperatures is thought to be generall phenomenon in measuring the resistivity of graphite, because the atmosphere dependence was also observed for other artificial graphites.
