Magneto-volume effects in Fe-Cu solid solutions

The magnetic properties of Fe-Cu metastable solid solutions have been investigated by means of neutron diffraction and magnetisation measurements. These compounds exhibit ferromagnetic order with Curie temperatures above room temperature for concentrations beyond 40 at % in Fe. The magnetic moment at 5 K can reach values over 2 mu(B), while the high field susceptibility is similar to that Found in FCC-FeNi Invar alloys. These features together with the low values for the linear coefficient for thermal expansion in the ferromagnetic region suggest that magneto-volume anomalies, including Invar behaviour, play a major role in the magnetic properties of this system when the crystal structure is face centred cubic. Such behaviour Could be explained using theoretical total-band energy calculations. (c) 2005 Elsevier B.V. All rights reserved.