High-Pressure Coupling Reactions to Produce a Spherical Bulk Re x N/Fe 3 N Composite

We report a novel high-pressure coupling (HPC) reaction that couples the nitridation of Re with high-pressure solid-state metathesis (HPSSM) of Fe N to produce a spherical bulk Re N/Fe N composite. Compared with conventional methods, upon coupling of the HPSSM reactions, the synthetic pressure for Re nitridation was successfully reduced from 13 to 10 GPa (for Re N) and from 20 to 15 GPa (for Re N). The product Re N species would be surrounded by product Fe N, resulting in a spherical bulk Re N/Fe N composite ( = 2 or 3). The composite exhibits a soft magnetic behavior, and the content of nitrogen in Re N ( = 2 or 3) was controlled by adjusting the conditions. The HPC reaction establishes a new approach for the bulk synthesis of 5d transition metal nitride.