Gamma'-Fe4N exhibits fascinating magnetic properties. It adopts a simple perovskite-like structure (space group Pm-3m) with iron atoms occupying the corners (Wyckoff position 1b) and faces (3c) of the cubic cell and nitrogen in the octahedral centers (1b). Incorporation of nitrogen alters the magnetic properties from antiferromagnetism (AFM) for Gamma-Fe to ferromagnetism (FM) for Gamma'-Fe4N due to lattice expansion and change in the number of valence electrons. Recently we adopted a novel two-step ammonolytic reaction established by our group to synthesise SnxFe4?xN (up to x = 0.9) as a phase-pure powder. The first structural and magnetic characterisation of this new compound shows fascinating magnetic properties that presumably go back to a miscibility gap around x = 0.33 with a (magnetic) phase separation and ultimately lead to a spin glass behaviour at high Sn concentrations.