Three stable nitrogen-rich Ce-N compounds predicted from first-principles calculations at high pressure

Abstract

As a new type of environmentally friendly high energy density material, metal-doped nitrogen-rich compounds have drawn much attention in recent years in the field of scientific research due to their unique high pressure properties. In this paper, a first principle computational approach has been used to conduct an extensive structural search for energetically favorable structures in the Ce-N system. We finally discovered three new structures: Ce2N3 in the P21/m phase, CeN3 in the C2/m phase, CeN5 in the P phase. Among them, the C2/m-CeN3 structure remains kinetically stable at 0 GPa and can be quenched to ambient conditions after synthesis at high temperatures and pressures. The C2/m-CeN3 and P1¯-CeN5 compounds, which have significantly higher detonation velocities and pressures than TNT and HMX, can be used as potential energy materials. Their structures of P21/m-Ce2N3, C2/m-CeN3 and P1¯-CeN5 were successfully predicted, providing valuable references for synthesizing and exploring novel stable cerium-nitrogen compounds.