Magnetic Properties of Metastable bcc and fcc Fe-Cu Alloys Produced by Vapor Quenching

High concentration Fe 1- x Cu x alloys have been obtained by rf sputtering technique and investigated by X-ray diffraction and magnetization measurements. The bcc phase is extended over the region with x =0–0.4, while the fcc phase with x =0.6–1.0. For x =0.4–0.6, we have the mixed phase of bcc and fcc. The lattice constant of bcc phase increases slightly and that of fcc phase decreases with increasing x . In the bcc alloys, the average magnetic moment decreases with increasing x and deviates upwards from the simple dilution law. In the fcc alloys, the magnetic moment also decreases with increasing x but it deviates downwards from the simple dilution law. The Curie temperature, T c , of the Fe 1- x Cu x alloys decreases abruptly with increasing x : T c is higher than 750 K for the bcc alloys, while it is lower than 320 K for the fcc alloys and become 0 K at about x =0.92.