The production and structural characterization of gas-evaporated nanoparticles in the Fe 1−x Cr x system, with 0 Ͻ x Ͻ 0.83 are reported. The results show that for x ϳ 0.5 the metastable -FeCr can be stabilized and it constitutes up 60 wt % of the material. The sample with the highest -FeCr content is further analyzed to study the structural and the magnetic properties of this phase and its thermal stability. The -FeCr phase is weakly magnetic with an average magnetic moment of 0.1 B per Fe atom and a Curie temperature below ϳ60 K. It is stable up to 550 K where it starts to transform to bcc-FeCr. Annealing at 700 K yields Cr 2 O 3 due to Cr surface segregation and affects the magnetic behavior of the system, which is dominated by interparticle interactions.