The mechanical alloying process has been used to prepare nanocrystalline Cu70Fe18Co12 alloy from elemental Cu, Fe and Co powders in a planetary ball mill under argon atmosphere. The interdiffusion of Cu, Fe and Co leads to a heterogeneous solid solution with Cu-Fe-Co rich environments after 12 h of milling. The end product is a mixture of a highly disordered structure, fcc-Cu (Fe-Co), phase having different microstructural and structural parameters. For all the elaborate series, the evolution of coercive field and the remanence according to the time of milling is analyzed. The coercivity, Hc, decreases rapidly up to 8 h of milling to about 0.3 A/m and then the coercivity, increases to a maximum at 54 h. The influence of the time of milling at the resistivity of these alloys is shown.

The Cu70Co30 alloy was developed by a non-equilibrium method of "mechanical alloying", from a mixture of copper powder and pure cobalt. The nanostructured alloy Cu-Co with grains with a size of about 12 nm, has different electromagnetic properties which are often superior to those of conventional solid alloy, because of the critical size effect. In this work we are interested in the electromagnetic properties of the synthesized material. Resistivity, eddy current and the magnetization evolution were studied. The frequencies selected for plotting the diagram vary from 100 Hz to 100 kHz. To satisfy the Weiss condition, the excitation field must be of the same order of magnitude as the field that characterizes the area of Weiss. For all prepared series, the evolution of the magnetization as a function of milling time was analyzed. The influence of milling time on the resistivity variation is shown.