Magnetic and magnetocaloric properties of the double perovskite Sm-doped Ho2CoMnO6

The polycrystalline compounds Ho2-xSmxCoMnO6 (0 ≤ x ≤ 1) was synthesized by the conventional solid-state process. The structural study has been solved by X-ray powder diffraction (XRD) indicating that all studied samples adopt a monoclinic structure with the space group P21/n. The magnetic properties of the Ho2-xSmxCoMnO6 (0 ≤ x ≤ 1) compounds, show a ferromagnetic transition at the Curie temperature (TC), thus the latter increases with Sm doping. Finally, the magnetocaloric effect (MCE) study revealed that the maximum magnetic entropy change (-ΔSM)max, at TC under a magnetic-field-change (h = μ0ΔH) of 5 T, decreases with Sm doping from 4.97 to 1.86 J kg−1 K−1 for x = 0 to x = 1, respectively. The results show that Sm doping increases TC but lowers the magnetocaloric response, but obtained values of Relative Cooling Power (RCP) and adiabatic temperature (ΔTad) remain reasonably high. Hence, the investigated compounds, given their high stability and eco-friendly, could be promising materials for magnetic refrigeration technology. •Polycrystalline compounds Ho2-xSmxCoMnO6 (0 ≤ x ≤ 1) were synthesized by solid state reaction.•The structural, magnetic and magnetocaloric properties of these compounds have been studied.•Sm doping increased the transition temperature (TC), while it decreases the magnetocaloric properties.•Even if the magnetocaloric properties decrease by doping effect, these compounds remain useable in magnetocaloric refrigeration applications.