Granular alloys composed of nanoclusters of a magnetic element (e.g. Co, Fe, Ni) embedded in a non-magnetic metallic matrix (e.g. Cu, Au, Ag) present giant magnetoresistance (GMR). The GMR is caused by spin-scattering phenomena at the interfaces between magnetic granules and the matrix, and thus is closely correlated to microstructure of the samples. In melt-spun CoxCu100−x samples the GMR exhibits a maximum after annealing at the temperature of 450°C largely independent of the sample composition. The dynamics of the Co–Cu segregation process has directly been probed observing in situ annealing process of the samples in time resolved X-ray diffraction experiments. The results of accurate Rietveld analysis definitively demonstrated that the activation of Co–Cu remixing, when heating the samples around 500°C, is largely independent of the annealing kinetics.
Meneghini, C., A., G.P., Gubieda, M.L.F.D.E.Z., Mobilio, S. (2003). Time resolved X-ray diffraction experiments during annealing of Co15Cu85 granula alloy. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 262, 92-96 [10.1016/S0304-8853(03)00026-X].
Time resolved X-ray diffraction experiments during annealing of Co15Cu85 granula alloy
MENEGHINI, CARLO;MOBILIO, Settimio
2003-01-01
Abstract
Granular alloys composed of nanoclusters of a magnetic element (e.g. Co, Fe, Ni) embedded in a non-magnetic metallic matrix (e.g. Cu, Au, Ag) present giant magnetoresistance (GMR). The GMR is caused by spin-scattering phenomena at the interfaces between magnetic granules and the matrix, and thus is closely correlated to microstructure of the samples. In melt-spun CoxCu100−x samples the GMR exhibits a maximum after annealing at the temperature of 450°C largely independent of the sample composition. The dynamics of the Co–Cu segregation process has directly been probed observing in situ annealing process of the samples in time resolved X-ray diffraction experiments. The results of accurate Rietveld analysis definitively demonstrated that the activation of Co–Cu remixing, when heating the samples around 500°C, is largely independent of the annealing kinetics.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
