Structural, magnetic, and magnetocaloric properties of Ag-doped in the La0.6Ca0.4MnO3 compound

Highlights: • All samples crystallize in an orthorhombic symmetry with Pnma space group. • At low temperatures, the behavior is irreversible with low divergence between M (T) – ZFC and M (T) – FC. • The RCP varied from 221 to 264 J kg−1 under an applied magnetic field of 5 T for La_0.6Ca_0.4MnO₃ and La_0.6Ca_0.3Ag_0.1MnO_3, respectively. • Following Banerjee's criterion, we assume that the FM–PM phase transition in these systems is basically of second-order for La_0.6Ca_0.4MnO₃ and first-order for La_0.6Ca_0.3Ag_0.1MnO₃ samples. We present a study of the physical properties of the La_0.6Ca_0.4MnO₃ and La_0.6Ca_0.3 Ag_0.1MnO₃ powder samples. Our synthesized samples were prepared by sol–gel methods. They crystallize in the orthorhombic perovskite structure with Pnma space group. The substitution of calcium by silver induces an increase in cell volume. The magnetocaloric effect was estimated from the magnetic isotherms. With 10% of Ag doped in the La_0.6Ca_0.4MnO₃, we can observe a significant maximum variation of the magnetic entropy −ΔS_Max and a relative cooling power RCP near room temperature under an applied magnetic field of 5 T. The RCP varied from 221 to 264 J kg−1 under an applied magnetic field of 5 T for La_0.6Ca_0.4MnO₃ and La_0.6Ca_0.3Ag_0.1MnO_3, respectively. The comparison of the values, reported in the reference Gd material, underlines that the proposed oxide material has significant advantages for magnetic refrigeration.