Effect of Si/Ge ratio on resistivity and thermopower in Gd(5)Si(x)Ge(4-x) magnetocaloric compounds
DSpace at IIT Bombay
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Title |
Effect of Si/Ge ratio on resistivity and thermopower in Gd(5)Si(x)Ge(4-x) magnetocaloric compounds
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Creator |
KUMAR, DMR
RAJA, MM PRABAHAR, K CHANDRASEKARAN, V PODDAR, A RANGANATHAN, R SURESH, KG |
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Subject |
TRANSPORT-PROPERTIES
GD-5(SIXGE1-X)(4) PHASES GD-5(SI2GE2) TRANSITION ALLOYS Gd-Si-Ge alloy Phase transition Resistivity Thermopower |
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Description |
The effect of Si/Ge ratio on resistivity and thermopower behavior has been investigated in the magnetocaloric ferromagnetic Gd(5)Si(x)Ge(4-x) compounds with x = 1.7-2.3. Microstructural studies reveal the presence of Gd(5)(Si, Ge)(4)-matrix phase (5:4-type) along with traces of secondary phases (5:5 or 5:3-type). The x = 1.7 and 2.0 samples display the presence of a first order structural transition from orthorhombic to monoclinic phase followed by a magnetic transition of the monoclinic phase. The alloys with x = 2.2 and 2.3 display only magnetic transitions of the orthorhombic phase. A low temperature feature apparent in the AC susceptibility and resistivity data below 100 K reflects an antiferromagnetic transition of secondary phase(s) present in these compounds. The resistivity behavior study correlates with microstructural studies. A large change in thermopower of -8 mu V/K was obtained at the magneto-structural transition for the x = 2 compound. (C) 2011 Elsevier B.V. All rights reserved.
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Publisher |
ELSEVIER SCIENCE BV
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Date |
2012-06-26T07:18:33Z
2012-06-26T07:18:33Z 2011 |
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Type |
Article
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Identifier |
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS,323(13)1750-1754
0304-8853 http://dx.doi.org/10.1016/j.jmmm.2011.01.017 http://dspace.library.iitb.ac.in/jspui/handle/100/14116 |
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Language |
English
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