Structural and magnetization changes at high temperature in Co50Mn30In20 alloy

In this work we report on microstructural and magnetic characterization of Co50Mn30In20 alloy meltspun ribbons in its as-cast state and after being annealed at 923 K during 5 h. Microstructure was analysed by means of differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques, while magnetic measurements (hysteresis loop and magnetization) were performed in the temperature range 1.8–1000 K. XRD measurements confirm the presence of Heusler phase Co2MnIn in the annealed material with crystallites sizing around 35 nm. Ferromagnetic ordering temperatures in Co-based Heusler systems (Co2MnIn) are considerably higher than in the corresponding Ni2MnIn ones. In this case, TC = 520 K for the annealed sample is lower than the corresponding one (TC = 550 K) for the as-cast ribbon. At around 840 K, the very abrupt magnetization change for the annealed sample is higher than the one obtained for the as-cast ribbon. This temperature value is the same than the recrystallization phase transition temperature detected in the DSC measurement.Peer reviewe