Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8162655 | Physica B: Condensed Matter | 2014 | 33 Pages |
Abstract
La0.67âxDyxPb0.33MnO3 (x=0.00, 0.15 and 0.20) compounds were prepared using solid-state reaction. X-ray diffraction and magnetic measurements were used to investigate the effects of Dy doping on the physical properties of La0.67âxDyxPb0.33MnO3. XRD data have been analyzed by Rietveld refinement technique. Results have shown that all obtained perovskite manganites were a single phase. Moreover they crystallized in a rhombohedric structure with R3¯c space group. Magnetization as a function of temperature has shown that these compounds exhibit a transition from a ferromagnetic to paramagnetic phase with increasing temperature. A magnetocaloric effect in the obtained samples has been deduced by two methods: Classical Maxwell relation and Landau theory. The maximum of magnetic entropy change |ÎSMmax| in a magnetic field change of 5 T is found to be 4.26 J kgâ1 Kâ1 at 360 K, 3.51 J kgâ1 Kâ1 at 290 K and 2.3 J kgâ1 Kâ1 at 277 K for x=0.00, 0.15 and 0.20, respectively. At this value of magnetic field, the relative cooling power (RCP) is found to be 292, 246 and 215 J kgâ1 for x=0.00, 0.15 and 0.20, respectively. Our result on magnetocaloric properties suggests that La0.67-xDyxPb0.33MnO3 (x=0.00, 0.15 and 0.2) compounds are attractive as possible refrigerants for near room temperature magnetic refrigeration.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
N. Zaidi, S. Mnefgui, A. Dhahri, J. Dhahri, E.K. Hlil,