Identification of a Ternary Nitride Ti₁₀Cu₃N₄ with a Unique Structure Type

This study presents the synthesis and detailed structural analysis of the ternary nitride Ti10Cu3N4. Initially identified as Ti3CuN within the Ti–Cu–N ternary phase diagram, its crystal structure remained unresolved and was characterized solely as belonging to the tetragonal crystal system. Through a comprehensive structural analysis, this study proposes a revised stoichiometry as Ti10Cu3N4; its crystal structure represents a previously unreported structure type within the P42/mnm space group. Its atomic arrangement was elucidated through a combination of X-ray powder diffraction profile analysis and density functional theory calculations, corroborated by neutron diffraction studies. Furthermore, the hydrogen storage properties of Ti10Cu3N4 were characterized, demonstrating a hydrogen absorption capacity of approximately 0.6 wt % with desorption occurring in the temperature range of 200–550 °C.