Composite materials; Magnetic refrigeration; Magnetocaloric effect; Nanocrystalline manganites; Phase transitions
Abstract :
[en] Poly- and nanocrystalline manganite composites (1/3)La0.7Ca0.3MnO3 and /
(2/3)La0.8Sr0.2MnO3 prepared by the sol-gel method are studied by magnetic and transport
measurements. The Arrott plots and universal curve of magnetic entropy change confirm that
magnetic transition is of the second order. The magnetocaloric effect of polycrystalline
composite is found to be roughly twice smaller as compared to the polycrystalline Ca- and Srbased
parent phases. The nanocrystalline composite of the same composition exhibits only 8
% reduction of magnetic entropy change. Due to the large temperature spread of
magnetocaloric effect the relative cooling power RCP of nanocrystalline composite is about
three times larger as compared to the nanocrystalline Ca- and Sr- based parent phases. The
maximum magnetic entropy change DSMAX and relative cooling power RCP are found to be
more sensitive to magnetic field strength for the nano- than for polycrystalline composites
studied.
Research Center/Unit :
SUPRATECS - Services Universitaires pour la Recherche et les Applications Technologiques de Matériaux Électro-Céramiques, Composites, Supraconducteurs - ULiège
Disciplines :
Materials science & engineering Physics
Author, co-author :
Pękała, M; University of Warsaw, Poland > Department of Chemistry
Pękała, K; Warsaw Technical University, Poland > Faculty of Physics
Drozd, V; Florida International University, United States > Center for Study Matter at Extreme Conditions
Fagnard, Jean-François ; Université de Liège - ULiège > Dép. d'électric., électron. et informat. (Inst.Montefiore) > Capteurs et systèmes de mesures électriques
Vanderbemden, Philippe ; Université de Liège - ULiège > Dép. d'électric., électron. et informat. (Inst.Montefiore) > Capteurs et systèmes de mesures électriques
Language :
English
Title :
Effect of nanocrystalline structure on magnetocaloric effect in manganite composites (1/3)La0.7Ca0.3MnO3/(2/3)La0.8Sr0.2MnO3
Publication date :
25 April 2015
Journal title :
Journal of Alloys and Compounds
ISSN :
0925-8388
eISSN :
1873-4669
Publisher :
Elsevier Science, Lausanne, Switzerland
Special issue title :
Journal of Alloys and Compounds
Volume :
629
Pages :
98-104
Peer reviewed :
Peer Reviewed verified by ORBi
Funders :
WBI - Wallonie-Bruxelles International Polish Government
