학술논문

The existence of giant magnetocaloric effect and laminar structure in Fe.sub.73.5- .sub.x Cr.sub.x Si.sub.13.5B.sub.9Nb.sub.3Cu.sub.1
Document Type
Report
Source
Journal of Magnetism and Magnetic Materials. Sept, 2006, Vol. 304 Issue 1, p36, 5 p.
Subject
Atmospheric turbulence -- Magnetic properties
Nanotechnology -- Magnetic properties
Language
English
ISSN
0304-8853
Abstract
To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jmmm.2006.02.006 Byline: N. Chau (a), P.Q. Thanh (b), N.Q. Hoa (a), N.D. The (a) Keywords: Soft magnetic amorphous system; Nanocrystalline materials; Magnetocaloric effect; Magnetic properties of nanostructures Abstract: Amorphous soft magnetic ribbons Fe.sub.73.5- .sub.x Cr.sub.x Si.sub.13.5B.sub.9Nb.sub.3Cu.sub.1 (x=1-5) have been fabricated by rapid quenching on a single copper wheel. The differential scanning calorimetry (DSC) patterns showed that the crystallization temperature of [alpha]-Fe(Si) phase is ranging from 542 to 569[degrees]C, a little higher than that of pure Finemet (x=0). With the same annealing regime, the crystallization volume fraction as well as the particle size of [alpha]-Fe(Si) crystallites decreased with increasing Cr amount substituted for Fe in studied samples. Especially, the interesting fact is that the laminar structure of heat-treated ribbons on the surface contacted to copper wheel in the fabricating process has been firstly discovered and explained to be related to the existence of Cr in studied samples. The hysteresis loop measurement indicated that there is the pinning of displacement of domain walls. The giant magnetocaloric effect (GMCE) has been found in amorphous state of the samples. After annealing, the soft magnetic properties of investigated nanocomposite materials are desirably improved. Author Affiliation: (a) Center for Materials Science, College of Science, Vietnam National University, Hanoi, 334 Nguyen Trai, Hanoi, Vietnam (b) Department of Physics, College of Science, Vietnam National University, Hanoi, 334 Nguyen Trai, Hanoi, Vietnam