The influence of chemical composition on the magnetic properties of Fe1.5−xCoxRh0.5Mo3N (0 ≤ x ≤ 1.5)

Abstract

The system Fe_1.5−xCo_xRh_0.5Mo₃N has been studied by neutron diffraction, magnetometry, Mössbauer spectroscopy and transport measurements in order to follow the variations in the electronic properties as cobalt is added to ferromagnetic Fe_1.5Rh_0.5Mo₃N. The Curie temperature is maximised (132 K) when x = 0.5, although the saturation magnetisation decreases with increasing cobalt content. Co_1.5Rh_0.5Mo₃N does not show long-range magnetic order above 5 K. All compositions show metallic conductivity and the temperature dependence of the internal hyperfine fields in iron-rich compositions can be fitted using the Stoner model. The change in behaviour observed for x > 0.9 is attributed to the dominance of antiferromagnetic interactions in cobalt-rich regions.