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FIZIKA A 15 (2006) 1 , 1-16
 
THE ORIGIN OF THE SURFACE FIELD ENHANCED COERCIVE FIELD
IN NANOPHASE Fe73.5Cu1Nb3Si15.5B7 RIBBON
STJEPAN SABOLEK1, EMIL BABIĆ, IVICA KUŠEVIĆ,
MARKO ŠUŠAK, DARIO POSEDEL and DENIS STANIĆ
Department of Physics, Faculty of Science,
University of Zagreb, Bijenička 32, 10 000 Zagreb, Croatia
1E-mail address: sabolek@phy.hr
Received 1 September 2004; revised manuscript received 13 December 2004
Accepted 20 December 2004 Online 10 November 2006
The influence of surface fields Hp (generated with either
direct or alternating core-current) on soft magnetic properties
of amorphous and nanocrystalline Fe73.5Cu1Nb3Si15.5B7
ribbon has been studied.
While in amorphous ribbon the coercive field Hc
decreases with Hp, in the same optimally annealed ribbon
(Hc = 1.3 A/m, Mm » Ms)
Hc increases with Hp and the hysteresis
loss E decreases with Hp for all explored types
of Hp (static and dynamic with
different phases with respect to that of the magnetizing field H).
The unexpected increase of Hc in nanocrystalline ribbon
is associated to the influence of Hp on the surface
and main (inner) domain structure.
The model is developed which takes into account this interaction
and explains all experimental results.
The probable adverse effect of the external fields with configurations
similar to those of Hp on the performance of such ribbons is briefly
discussed and some procedures which can prevent these effects are proposed.
PACS numbers: 75.50.Kj, 75.60.Ch
UDC 538.945, 538.911
Keywords:
Fe73.5Cu1Nb3Si15.5B7, amorphous and nanocrystalline,
hysteresis loop, domain structure, domain wall pinning, coercive field,
core current
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