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MA: Magnetismus

MA 8: Hart- und Weichmagn. Materialien / Legierungen

MA 8.6: Vortrag

Dienstag, 12. März 2002, 15:00–15:15, H10

Magnetic properties of amorphous Nd-Fe-Co-Al alloys — •G. Kumar, J. Eckert, S. Roth, W. Löser, and L. Schultz — IFW Dresden, Institute of Metallic Materials, D-01171 Dresden, Germany

The amorphous alloys Nd₆₀Fe_xCo_30−xAl₁₀ (x = 0, 2.5, 5, 7.5, 10, 15) were prepared by copper mould casting and melt spinning. Structural, thermal, and magnetic properties were studied by different analytical techniques like XRD, DSC, SEM, TEM, and VSM. Isothermal and isochronal DSC experiments in conjunction with XRD were used to identify the crystalline phases. Magnetization as a function of temperature and field (at different temperatures) has been studied from 10-300 K. These measurements show the presence of two magnetic phases with ordering temperatures of 40 K and 474 K in all the investigated alloys. A step in the M-H hysteresis loops at temperatures below 80 K supports the presence of two magnetic phases. The coercivity versus temperature plot exhibits a peak at about 50 K. The correlation of coercivity and domain wall pinning is critically discussed.