Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8158072 | Journal of Magnetism and Magnetic Materials | 2013 | 5 Pages |
Abstract
Fe-Ni-Co alloys of various compositions (FexNi80âxCo20,x=20-50) were synthesized by using a sodium borohydride reduction route. The phase purity and crystallite size was ascertained by using powder X-ray diffraction (XRD). The alloys crystallize in the face centered cubic (fcc) structure with lattice parameters, a=3.546-3.558Â Ã
. The XRD line broadening indicates the fine particle nature of the materials. The estimated crystallite sizes were found to be 27.5, 27, 24, and 22.8Â nm for x=20, 30, 40, and 50; alloys respectively. Scanning electron micrograph studies indicates particle sizes to be in the range of 83-60Â nm for Fe-Ni-Co alloys. The values of saturation magnetization for FexNi80âxCo20 are found to be in the range of 54.3-41.2Â emu/g and are significantly lower than the bulk values (175-180Â emu/g). The coercivity decreases from 170 to 122Â Oe with decrease in Fe content. The observed magnetic behavior has been explained on the basis of size, surface effects, spin canting and the presence of superparamagnetic fractions in the ultrafine materials.
Keywords
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Shankar B. Dalavi, J. Theerthagiri, M.Manivel Raja, R.N. Panda,