Spherical-like bulk epsilon-Fe3-xCoxN (x = 0.0, 0.25, 1.95) alloys have been synthesized through high-pressure solid-state metathesis (HPSSM) reactions at 5 GPa and 1673 K, employing Fe2O3, CoO and hBN as reaction precursors. The as-prepared nitrides epsilon-Fe3-xCoxN crystallizes isostructural to epsilon-Fe3N as evidenced by powder X-ray diffraction (RXPD) and high-resolution transmission electron microscope (HRTEM). A detailed X-ray photoelectron spectroscopy (XPS) study of the as-prepared nitrides reveal that both binary epsilon-Fe3N and ternary epsilon-Fe3-xCoxN have metallic form Fe character due to the diffusion of nitrogen from the idea 2c interstitial site, but no evidence for the exists of metallic form Co-0 in the ternary epsilon-Fe3-xCoxN nitrides. We also find that the enhancement of Ms and He with the increase of Co at% in epsilon-Fe3-xCoxN may be due to the altered micro structural and exchange interactions. (C) 2017 Elsevier B.V. All rights reserved.