We report on the formation by mechanical alloying of fcc solid solution of Fe and Cu, which are immiscible. Intense codeformation of Cu with Fe and other high-melting bcc metals generates small fragments with tip radii of the order 1 nm such that capillary pressures force the atoms on these fragments to dissolve. The critical radius for dissolution is found to increase with solute content inside the spinodal thus leading to full dissolution of one of the components. The fcc-FeCu solid solutions have Curie temperatures similar to those of vapor-deposited alloys and a positive heat of mixing that is in accord with theoretical results.

• Received 11 February 1992

DOI:https://doi.org/10.1103/PhysRevLett.68.2235