Ferromagnetism in the filled β-Mn phase Fe2−xRhxMo3N

Abstract

Compositions in the solid solution Fe_2−xRh_xMo₃N which adopt the filled β-manganese structure have been prepared by the reductive nitridation of mixed binary metal oxides; single-phase samples can be prepared for 0.3 ≤ x ≤ 0.75. Those compositions with x ≤ 1 have been shown, by a combination of magnetometry, neutron diffraction and μSR, to be ferromagnetic at low temperatures. The Curie temperature is highest (T_c = 110 K) for x = 0.5, with a saturation magnetisation of 2.26(1) μ_B per formula unit. These compositions display metallic behaviour, with a change in the temperature gradient of the resistivity being observed at the Curie temperature. Fe_0.5Rh_1.5Mo₃N is also metallic but does not show long-range magnetic order.