Methods of Increasing the Measurement Accuracy during the Experimental Determination of the Melting Point of Graphite
Source: High Temperature, Volume 42, Number 1, January 2004 , pp. 60-67(8)
Abstract:The experimental procedure involving pulsed laser heating is realized, which enables one to investigate phase transformations in graphite and eliminates the homogeneous condensation of carbon vapor over a sample. Data are obtained on the melting point of graphite and the temperature of crystallization of liquid carbon at a pressure of 15 MPa. The absence of a difference between the melting point of graphite at a heating rate of 100 MK/s and the temperature of crystallization of liquid carbon at the cooling rate of the melt bath of 1.6 MK/s is revealed, which is indicative of the quasi-equilibrium of the melting process. In view of this, the temperature data are averaged by a unified value of 4800±100 K. It is shown that, during the crystallization of carbon melt, highly ordered graphite with crystallites up to 250 @[mu]m in size is formed in a liquid film 5 @[mu]m thick on a graphite substrate.
Document Type: Research Article
Affiliations: 1: Institute of High Energy Density, IVTAN (Institute of High Temperatures) Scientific Association, Russian Academy of Sciences, Moscow, 125412 Russia 2: Institute of High Temperatures, Russian Academy of Sciences, Moscow, 125412 Russia
Publication date: January 1, 2004