The production and structural characterization of gas-evaporated nanoparticles in the Fe1-xCrx system, with 0 < x < 0.83 are reported. The results show that for x similar to 0.5 the metastable sigma-FeCr can be stabilized and it constitutes up 60 wt % of the material. The sample with the highest sigma-FeCr content is further analyzed to study the structural and the magnetic properties of this phase and its thermal stability. The sigma-FeCr phase is weakly magnetic with an average magnetic moment of 0.1 mu(B) per Fe atom and a Curie temperature below similar to 60 K. It is stable up to 550 K where it starts to transform to bcc-FeCr. Annealing at 700 K yields Cr2O3 due to Cr surface segregation and affects the magnetic behavior of the system, which is dominated by interparticle interactions.