Influence of Dy addition on the magnetocaloric effect of La0.67Ca0.33Mn0.9V0.1O3 ceramics
DSpace at IIT Bombay
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Title |
Influence of Dy addition on the magnetocaloric effect of La0.67Ca0.33Mn0.9V0.1O3 ceramics
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Creator |
NISHA, P
PILLAI, SS SURESH, KG VARMA, MR |
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Subject |
X-ray diffraction
Reitveld refinement Magnetocaloric effect Relative cooling power MAGNETIC-PROPERTIES TEMPERATURE |
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Description |
The influence of partial substitution of La by Dy on the magnetocaloric response of (La1-xDyx)(0.67)Ca0.33Mn0.9V0.1O3, where x=0.03, 0.15 and 0.25 is studied. Rietveld refinement of X-ray diffraction pattern using GSAS method shows that the compounds adopt the orthorhombic structure with Pnma space group. The systematic change in lattice parameters and magnetic phase transition indicates the substitution effect of Dy. From the magnetization isotherms at different temperatures, magnetic entropy change close to their respective transition temperatures (T-C) has been evaluated. The maximum value of entropy change near T-C is found to be about 4.8 J/kg K at 187.5 K for LCMVDy0.03, 2.45 J/kg K at 107.5 K for LCMVDy0.15 and 2.15 J/kg K at 92.5 K for LCMVDy0.25 at 4 T. Dy addition produces a reduction in T-C and in magnitude of the magnetic entropy change. Even though the entropy change decreases with increasing Dy substitution the refrigerant temperature range, Delta T, is found to be 10 K for LCMVDy0.03, 31 K for LCMVDy0.15 and 35 K for LCMVDy0.25 compounds [90%] at 4 T. The field dependence of the magnetic entropy change is also analyzed showing the power law dependence, Delta S-M infinity H-n where n=0.75(2) for LCMVDy0.03, n=0.80(4) for LCMVDy0.15 and n=0.92(8) for LCMVDy0.25 compounds at their respective transition temperatures. The relative cooling power and its field dependance are also analyzed. (C) 2011 Elsevier B.V. All rights reserved.
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Publisher |
ELSEVIER SCIENCE BV
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Date |
2014-10-15T14:05:20Z
2014-10-15T14:05:20Z 2012 |
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Type |
Article
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Identifier |
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 324(1)37-43
http://dx.doi.org/10.1016/j.jmmm.2011.07.032 http://dspace.library.iitb.ac.in/jspui/handle/100/15058 |
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Language |
en
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