Vibrational and magnetic properties of supersaturated Cu100-xFex

We investigated the atomic dynamics and the magnetic properties of the Cu100-xFex system. Samples with nominal Fe concentrations of 5, 17.5, 30 and 45 at. % were prepared in the same manner by mechanical alloying in a planetary ball mill. All samples are nanocrystalline supersaturated solid solutions, without crystalline bcc Fe phase or amorphous matrix. They have both ferromagnetic and antiferromagnetic order at 5 K, but the antiferromagnetic state transforms to a paramagnetic one well below room temperature. The inelastic neutron scattering measurements were performed at room temperature at FOCUS (PSI, SINQ). With increasing Fe concentration we additionally observed low-energy, most likely transverse modes in the dynamic structure factor. (orig.)