Electron transport properties of Co71−xFexCr7Si8B14 (x=0, 2, 3.2, 4, 6,8 and 12 at%) amorphous alloys during devitrification

Panda, A K and Kumari, Seema and Chattoraj, I and Ghosh, M and Mitra, A (2007) Electron transport properties of Co71−xFexCr7Si8B14 (x=0, 2, 3.2, 4, 6,8 and 12 at%) amorphous alloys during devitrification. Journal of Magnetism and Magnetic Materials, 308 (1). pp. 65-70.

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The investigation addresses the electron transport properties of Co71−xFexCr7Si8B14 (x=0, 2, 3.2, 4, 6, 8 and 12 at%) amorphous alloys. The variation in electrical resistivity of as-cast amorphous materials with thermal scanning from room temperature to 1000 K was measured. The CoFe-based alloys revealed an initial decrease in temperature coefficient of resistivity (TCR), a characteristic of spin-wave phenomena in glassy metallic systems. This behaviour in the present alloys was in a sharp contrast to the Co-based amorphous materials that indicate the drop in resistivity much below room temperature. In the studied alloys, the variation in initial TCR values and the full-width at half-maxima determined from X-ray diffraction of as-quenched materials exhibited a similar trend with increasing Fe content, indicating the compositional effect of near neighbouring atoms. After the initial decrease in resistivity, all the alloys indicated a subsequent increase at Tmin. The Curie temperature (TC), which was measured from thermal variation of ac susceptibility showed non-monotonic change with Fe content. In the temperature range between Tmin and TC the relative scattering by electron-magnon and electron-phonon resulted in the non-monotonic change in Curie temperature. At crystallization onset (TX1) all the alloys except there with X=6, showed a sharp decrease in electrical resistivity which was attributed to ordering phenomena. In contrast to this resistivity decrease, X=6 alloy exhibited a drastic increase in resistivity around TX1 observed during amorphous to nanocrystalline transformation. Such nanocrystalline state was observed by Transmission electron microscopy.

Item Type:Article
Official URL/DOI:http://dx.doi.org/10.1016/j.jmmm.2006.04.036
Uncontrolled Keywords:Amorphous alloys; Curie temperature; Electrical resistivity; Spin-waves; Electron-magnon; Electron-phonon
Divisions:Material Science and Technology
ID Code:621
Deposited By:Sahu A K
Deposited On:02 Jun 2010 11:12
Last Modified:06 Feb 2012 17:41
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