Study and Preliminary Application of the Thermochemical 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, we propose a novel, high-precision and low-cost method for quantitatively determining the equation of state of C₃N₄, based on decomposition phase boundary and compression line at room temperature. We constructs the 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, we make 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 novel nitrogen-rich explosives. It significantly reduces 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.