Beneficial effect of Mn-substitution on magnetic and magnetocaloric properties of La0.5Sr0.5CoO3 ceramics

In this paper, we present studies of the influence of B-site substitution of Mn (5% and 10%) on magnetic and magnetocaloric properties of La0.5Sr0.5CoO3. Polycrystalline samples of La0.5Sr0.5Co1-xMnxO3 (x = 0, 0.05, 0.1) are synthesized via solid state reaction route. Ferromagnetism is observed in all the compounds with enhancement in magnetisation and simultaneous effect of lowering of TC from 243 K to 235 K through increase in Mn content from 0 to 10%. Ferromagnetic hysteresis is noticed in all cases with significant rise in the value of remanent magnetisation (Mr) from 4180 emu/mol for x = 0–5750 emu/mol for x = 0.1. Magnetocaloric effect (MCE) is observed with peaks in temperature dependent magnetic entropy change curves (-ΔSM ~ T) appearing at TC. However, the peaks undergo shift to higher temperatures for higher field changes due to possible augmented short range interactions among ferromagnetic clusters taking place above TC that effectively modifies TC to a larger value. Both −ΔSMmaxand RCP (Relative Cooling Power) record increase with values lying in the ranges 2.64–2.74 J/kg/K and 159.48–177.66 J/kg respectively for ΔH = 6 T corresponding to Mn content x = 0–0.1. Such remarkable features predict their potential application in magnetic refrigeration technology. Moreover, these materials are quite exciting from basic physics point of view.