Berlin 2005 – wissenschaftliches Programm
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MA: Magnetismus
MA 29: Magnetische Materialien
MA 29.11: Vortrag
Dienstag, 8. März 2005, 17:45–18:00, TU A060
Magnetization of bulk SmCo5−xCux (x ≈ 2.5) in high pulsed fields — •P. Kerschl1, A. Handstein1, K. Khlopkov1, O. Gutfleisch1, R. Grössinger2, K.-H. Müller1, and L. Schultz1 — 1IFW Dresden, Institut für Metallische Werkstoffe, PF 270116, D-01171 Dresden, Germany — 2TU Wien, Institut für Festkörperphysik, Wiedner Hauptstr. 8-10, A-1040, Wien, Austria
The substitution of Co by Cu in SmCo5 is
known to cause a considerably large coercivity JHc in
this material even in the as-cast state. In this study the phase
composition and microstructure have been investigated by XRD, SEM
and EDX analysis. Induction melted samples of SmCo5−xCux
(x = 2.5, 3) show a phase separation within the 1:5 structure
exhibiting different Sm/(Co,Cu) ratios. Magnetization measurements
were performed in a pulsed high-field facility up to 50 T with a
rise time of about 8.5 ms. A jump from low to high magnetization
state in an increasing external field at the transition field
Hu is observed in the samples with x = 2.5 and 3. The values of
JHc and Hu increase with decreasing temperature and with
increasing field sweep rate. High coercivities up to about
µ0JHc ≈ 30 T and high transition fields
µ0Hu reaching 45 T at 4.2 K for x = 3 are observed.
Indications for the connection between the high field transition
at Hu and the observed microstructure are presented. The
influence of the field changing rate on the observed coercivity is
discussed with respect to a possible pinning mechanism.
This work was supported by the BMBF project 03SC5DRE.