The effect of Dy doped on structural, magnetic and magnetocaloric properties of La0.67−xDyxPb0.33MnO3 (x=0.00, 0.15 and 0.20) compounds

Abstract

La0.67−xDyxPb0.33MnO3 (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 La0.67−xDyxPb0.33MnO3. 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 |ΔSMmax| in a magnetic field change of 5T is found to be 4.26Jkg−1K−1 at 360K, 3.51Jkg−1K−1 at 290K and 2.3Jkg−1K−1 at 277K 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 215Jkg−1 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.