Ultrasoft magnetic properties in nanocrystalline alloy Finemet with Au substituted for Cu

The amorphous ribbon Fe(73.5)Si(13.5)B(9)Nb(3)Au(1) has been prepared by rapid cooling on a copper wheel. The ribbon is 16.8 mu m thick and 7 mm wide. The DSC curves show the first peak at 547-579 degrees C (corresponds to the crystallization of alpha-Fe(Si) phase) depending on heating rate from 10 to 50 degrees C/min which is a little higher than that of pure Finemet (542-570 degrees C, respectively). From the Kissinger plot, the crystallization activation energy is determined and shown to be 2.8 eV for alpha-Fe(Si) phase, less than that of Finemet (E = 3.25 eV). By annealing at 530 degrees C for 30, 60 and 90 min, the crystallization volume fraction of alpha-Fe(Si) phase increased from 73% to 78% and 84%, respectively. After appropriate annealing, the ultrasoft magnetic properties are achieved. The maximum magnetic entropy change, vertical bar Delta S(m)vertical bar(max), showed a giant value of 7.8 J/kg K which occurred at around Curie temperature of amorphous phase of the ribbon. (C) 2006 Published by Elsevier B. V.

Title: 

	Ultrasoft magnetic properties in nanocrystalline alloy Finemet with Au substituted for Cu
Authors:	N. Chau N.Q. Hoa N.D. The P.Q. Niem
Keywords:	Nanocrystalline alloy Soft magnetic amorphous system Nanoparticle Magnetocaloric effect
Issue Date:	2006
Publisher:	ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Citation:	ISIKNOWLEDGE
Abstract:	The amorphous ribbon Fe(73.5)Si(13.5)B(9)Nb(3)Au(1) has been prepared by rapid cooling on a copper wheel. The ribbon is 16.8 mu m thick and 7 mm wide. The DSC curves show the first peak at 547-579 degrees C (corresponds to the crystallization of alpha-Fe(Si) phase) depending on heating rate from 10 to 50 degrees C/min which is a little higher than that of pure Finemet (542-570 degrees C, respectively). From the Kissinger plot, the crystallization activation energy is determined and shown to be 2.8 eV for alpha-Fe(Si) phase, less than that of Finemet (E = 3.25 eV). By annealing at 530 degrees C for 30, 60 and 90 min, the crystallization volume fraction of alpha-Fe(Si) phase increased from 73% to 78% and 84%, respectively. After appropriate annealing, the ultrasoft magnetic properties are achieved. The maximum magnetic entropy change, vertical bar Delta S(m)vertical bar(max), showed a giant value of 7.8 J/kg K which occurred at around Curie temperature of amorphous phase of the ribbon. (C) 2006 Published by Elsevier B. V.
Description:	JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS Volume: 304 Issue: 1 Pages: E179-E181 Published: SEP 2006 ; TNS07684
URI:	http://www.sciencedirect.com/science/article/pii/S030488530600271X http://repository.vnu.edu.vn/handle/VNU_123/31573
ISSN:	0304-8853
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