Effect of strontium deficiency on the structural, magnetic and magnetocaloric properties of La0.65Eu0.05Sr0.3-xMnO3 (0 <= x <= 0.15) perovskites

Autor: Aziz Dinia, Mohamed Oumezzine, E.K. Hlil, Guy Schmerber, Marwène Oumezzine, R. Bellouz
Přispěvatelé: Laboratoire Physico-Chimie des Matériaux [Monastir], Faculté des Sciences de Monastir (FSM), Université de Monastir - University of Monastir (UM)-Université de Monastir - University of Monastir (UM), Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Magnétisme et Supraconductivité (MagSup), Institut Néel (NEEL), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2015
Předmět:
Zdroj: RSC Advances
RSC Advances, Royal Society of Chemistry, 2015, 5 (79), pp.64557-64565. ⟨10.1039/c5ra11395d⟩
ISSN: 2046-2069
DOI: 10.1039/c5ra11395d⟩
Popis: We have investigated the effect of nominal strontium deficiency on the structure, magnetic and magnetocaloric properties of La0.65Eu0.05Sr0.3-xMnO3 (x = 0, 0.10 and 0.15) perovskites. The nanocrystalline samples were prepared by the sol-gel-based Pechini method. Rietveld refinement of the X-ray diffraction patterns, shows the formation of single-phase compositions with rhombohedral symmetry (space group R (3) over barc, no. 167). Raman spectra at room temperature reveal a gradual change in phonon modes with increasing nominal strontium deficiency. All the samples undergo paramagnetic-ferromagnetic (PM-FM) transition. The Curie temperature decreases linearly with increasing x and changes from 355 K for x = 0 to 280 K for x = 0.15. Arrott plot analyses and a universal curve method were applied for studying the order of the magnetic transition in this system, found to be of second order. As strontium deficiency content increased further, peak entropy values were seen to decline. However, a simultaneous broadening of the Delta S-M(max) peaks led to enhanced relative cooling power (RCP) in the Sr-deficiency samples of up to 22% over that of La0.65Eu0.05Sr0.3MnO3. La0.65Eu0.05Sr0.15MnO3 exhibits the largest RCP value of 283 J kg(-1) at 280 K among the compounds investigated up to 5 T applied field. Through these results, La0.65Eu0.05Sr0.3-xMnO3 materials are strongly suggested for use as active refrigerants for magnetic refrigeration technology near and above room temperature.
Databáze: OpenAIRE
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