Itinerant Ferromagnet RhFe₃N: Advanced Synthesis and ⁵⁷Fe Mössbauer Analysis

Abstract

A novel two-step route for the synthesis of RhFe3N is presented that yields the target material with a significantly improved phase purity. Except from Fe0.5Rh0.5, the absence of other side products is exemplified on the basis of powder XRD, REM/EDX measurements, and Mössbauer investigations. As predicted from density-functional theory calculations, both Rietveld refinement and Mössbauer analysis show that the Rh atom within RhFe3N exclusively occupies Wyckoff position 1a but not 3c of the anti-perovskite-like structure in space group Pm3̅m, and the rhodium occupation of the 1a site is around 80%, yielding a precise formula of 1a(Rh0.8Fe0.2)3c(Fe3)1bN. The decomposition temperature of the nitride is estimated from temperature-dependent X-ray measurements to lie around 530 °C.