Magnetization evolution during thermal treatments of CoCu metastable alloys

Abstract We have studied the magnetization changes during the thermal treatment of CoxCu100−x (x=10,15) melt-spun alloys in a Faraday magnetometer. The evolution of the magnetization points out that the Co segregation starts at 370°C and finishes at 550°C. Room temperature hysteresis loops and zero field cooling curves performed in a SQUID magnetometer on samples as-quenched and annealed at 450°C and 500°C reveal the presence of Co particles, around 2 nm in radius, and a ferromagnetic phase. For sample annealed at 550°C, when the Co segregation has already finished, a ferromagnetic behaviour is detected.