Magnetic interactions in Pr0.67Sr0.33MnO3 nanoparticles: mean-field theory vs. experiments

International audience ; This study presents the modelling of magnetocaloric effect of Pr0.67Sr0.33MnO3 nanoparticles by using the mean-field theory (MFT). Theoretical calculations were used around the Curie temperature (TC) to simulate the temperature dependence of magnetic entropy change under several applied magnetic fields. The obtained results were compared with experimental data computed using the Maxwell relation. Discrepancy between the two methods confirm the invalidity of MFT for modelling the magnetocaloric properties of Pr0.67Sr0.33MnO3 nanoparticles. This invalidity suggests the presence of critical fluctuations near the TC, which can be attributed to the presence of disordered surface and/or magnetic frustration, and highlights the limitation of the used model.