Investigation of the physical properties of carbon under high temperatures (experimental studies)

Key experimental studies (mainly pulse heating) aimed at obtaining the physical properties of the most refractory substance—graphite—in the temperature range of 2000–8000 K are discussed. The properties considered are enthalpy, input (Joule) energy, thermal expansion, specific heat, and electrical resistance, as well as their dependence on the level of applied pressure. The results obtained by pulsed current heating and laser pulse heating are compared. An abnormally high specific heat just before the melting point is recorded under fast (during microseconds) heating of graphite. These effects are presumably associated with the appearance of nonequilibrium defects. A connection between these anomalies and the explosive electron emission is noted.