New Forms of Carbon and Nonequilibrium Processing

Abstract

Studies on new carbon phases are reviewed from the point of view of non-equilibrium processing. First, phase diagram studies on carbon under high pressures and high temperatures are summarized in order of progress, and the known and the expected, unknown phases are listed as metastable phases sorted by bondings. Second, the SCARQ (shock compression and rapid quenching) by which we obtained new phases, n-diamond and 0.25-i-carbon, is introduced as a useful processing method to produce and to investigate new carbon phases. Third, we discuss the framework of how to investigate new carbon phases, comparing with common, essential factors in some non-equilibrium processes. We conclude that a cooling rate and constraint conditions are important and convenient to classify the processes.