Collapse of charge ordering and enhancement of magnetocaloric effect in La0.5Ca0.5−xAgxMnO3 (x = 0.0 and 0.2)

The present letter undertakes the analysis of the influence of the charge-ordering on the magnetic entropy change between La0.5Ca0.5MnO3 and La0.5Ca0.3Ag0.2MnO3 polycrystalline samples. The magnetic entropy change (ΔSM) of x = 0 alters the sign from negative to positive with the decrease in temperature below the charge ordering. However, ΔSM is negative and exhibits a peak close to TC in Ag-doped samples. The large RCP and ΔSM found in Ag-substituted samples were found to be interesting for magnetic refrigeration below room temperature. The obtained results were discussed within the framework of charge ordering and its destruction with Ag substitution.