Ab initio calculations of structural stabilities in the ternary Pr-Ta-N system

Ternary nitrides with the Ln-M-N composition (Ln = lanthanoid, M = Ta, W, Re) have garnered significant attention as potential candidates for novel superconducting materials due to their structural similarity to high-temperature superconducting oxides. Despite extensive research, experimental confirmation of superconductivity in these systems remains elusive.

To investigate the potential of Pr-Ta-N ternary nitrides as new superconducting materials, we employed density functional theory calculations. Our results unequivocally demonstrate the structural stability of the Ruddlesden-Popper phases Pr₂TaN₄, Pr₃Ta₂N₆, and PrTaN₂, while the perovskite phase PrTaN₃ was determined to be dynamically unstable. Furthermore, energy dispersion analysis revealed metallic nature in all stable compounds, suggesting the possibility of superconducting ground state.

These findings offer valuable theoretical insights into the properties of Pr-Ta-N ternary nitrides and provide a robust foundation for future experimental investigations aimed at realizing superconductivity in this class of materials.