Study and Preliminary Application of the Equation of State of C3N4

C3N4 has a wide range of applications in the synthesis of superhard materials and photocatalysis materials, but its phase transitions and physical behaviors under high pressure and high temperature conditions are not fully understood. Therefore, it is necessary to study its thermochemical equation of state. In this paper, a novel, high-precision and low-cost method is proposed for quantitatively determining the equation of state of C3N4, based on decomposition phase boundary and compression line at room temperature. This paper constructs equation of state for two phases of C3N4, and the corresponding physical quantities match well with first-principles calculations and experimental values, proving the reliability of the equation of state. Based on the equation of state of C3N4, this paper made a preliminary judgment on the phase state of the controversial points. Furthermore，this study attempts to incorporate the equation of state of C3N4 into the research on the detonation mechanism of the novel nitrogen-rich explosives. It significantly reduced the long-standing errors between the calculated values and experimental values of the detonation parameters of the explosives, and provides a new reference direction for the research on the detonation parameter calculations of new explosives.