Published January 15, 2015 | Version v1
Journal article

Effects of partial Mn-substitution on magnetic and magnetocaloric properties in Pr0.7Ca0.3Mn0.95X0.05O3 (Cr, Ni, Co and Fe) manganites

  • 1. Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax, Sfax University, B.P. 1171, 3000 Sfax (Tunisia)
  • 2. Higher Institute of Applied Sciences and Technology of Kasserine, Kairouan University, B.P. 471, 1200 Kasserine (Tunisia)
  • 3. Institut NEEL, B.P. 166, 38042 Grenoble Cedex 9 (France)

Description

Highlights: • Pr0.7Ca0.3Mn0.95X0.05O3(X = Cr, Ni, Co and Fe) ceramics were prepared by solid state method. • The manganite phases crystallize in an orthorhombic (Pnma) structure. • The samples exhibit a second order paramagnetic (PM)–ferromagnetic (FM) phase transition at the Curie temperature TC. • Maximum RCP equal to 405 J/kg observed for Pr0.7Ca0.3Mn0.95Cr0.05O3. • Second order phase transition is confirmed by Arrott plots and universal curves of entropy change. • The experimental ΔSM are well predicted by the phenomenological universal curve. - Abstract: Structural, magnetic and magnetocaloric properties of Pr0.7Ca0.3Mn0.95X0.05O3(X = Cr, Ni, Co and Fe) ceramics have been investigated by X-ray diffraction (XRD) and magnetic measurements. Powder samples have been elaborated using the solid state reaction method at high temperature. The Rietveld analysis of the powder X-ray diffraction shows that the samples crystallize in the orthorhombic structure with Pnma space group. Magnetic measurements show that all our materials exhibit a paramagnetic–ferromagnetic transition with decreasing temperature. The Arrott plots of ours materials reveal the occurrence of a second-order phase transition. The maximum values of magnetic entropy change |ΔSMmax| are 2.92, 2.96, 3.1, and 2.38 J kg−1 K−1 and the relative cooling power (RCP) values are 405.8, 378.2, 352.2 and 337.4 J kg−1 for a magnetic-field change from 0 to 5 T for Cr, Ni, Co and Fe respectively. The large RCP found in our substituted samples will be interesting for magnetic refrigeration over a wide temperature range ∼130 K around its paramagnetic to ferromagnetic transition temperature. With the scaling laws of ΔSM, the experimental ΔSM collapse onto a universal curve for several ceramics, where an average curve is obtained. With the phenomenological universal curve, the experimental ΔSM are well predicted for all materials

Availability note (English)

Available from http://dx.doi.org/10.1016/j.jallcom.2014.09.078

Additional details

Identifiers

DOI
10.1016/j.jallcom.2014.09.078;
PII
S0925-8388(14)02215-4;

Publishing Information

Journal Title
Journal of Alloys and Compounds
Journal Volume
619
Journal Page Range
p. 627-633
ISSN
0925-8388
CODEN
JALCEU

Optional Information

Copyright
Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.