  This work gives insights into processing and characterisation of bulk
nanocrystalline FeCr materials. The investigated FeCr alloys, consisting of 30,
50 and 70 at.% ferromagnetic Fe and remaining anti-ferromagnetic Cr, are
processed by arc melting and subsequent severe plastic deformation by high
pressure torsion. The physical similarities between elemental Fe and Cr in
combination with the nanocrystalline structure of the as-deformed alloys,
necessitates advanced characterisation techniques for the as-deformed state:
In-situ annealing synchrotron X-ray diffraction measurements as well as
electron microscopy experiments are linked to magnetostrictive measurements and
reveal a single phase microstructure. Surprisingly, the nanocrystalline FeCr
alloys remain supersaturated solid solutions upon annealing above 500{\deg}C,
meaning a decomposition in a FeCr nanocomposite is suppressed. For the chosen
annealing conditions grain growth is faster than decomposition and enhanced
magnetostrictive values are found compared to materials in the as-deformed
state.
