Magnetocaloric properties and Landau theory of Dy0.5(Sr1−xCax)0.5MnO3 (0≤x≤0.3) manganites at cryogenic temperatures

Highlights: • Magnetic entropy change of samples was investigated at low temperatures. • These samples show second-order transition phase. • A discord between experimental magnetic entropy change and Landau theory. Magnetic entropy change of Dy_0.5(Sr_1−xCa_x)_0.5MnO₃ nanoparticles (0 ≤ x ≤ 0.3) was analyzed at low temperatures to investigate the magnetic refrigeration as a promising tool for hydrogen liquefaction. These samples depict interesting values of maximum magnetic entropy change and large relative cooling power, especially for x = 0.3 sample (about 169 J/Kg). It could be a promising candidate for magnetic refrigeration at cryogenic temperatures. Landau theory presents a discord between the experimental magnetic entropy change and the theoretical one. This disagreement is tending to be in accordance as Ca substitution is increasing and also with augmenting the applied magnetic field.