Pr/ Co co-doping endows perovskite manganite with enhanced magnetic refrigeration capacity

It is recognized that new environmentally friendly and economical cooling methods are needed. In this paper, we focus on the effect of different doping amounts of Pr on the performance of magnetic refrigeration materials in the presence of trace doping of Co ions at the B-site. The samples La0.67Sr0.33−xPrxMn0.975Co0.025O3 (LSPMCO x = 0.10,0.125 and 0.15) in this paper were prepared by sol-gel method. The X-ray diffraction (XRD) and selected area electron diffraction (SAED) diffraction data determined that the samples were pure phases without impurities belonging to the R-3c space group (No. 167). Scanning electron microscope (SEM) and transmission electron microscope (TEM) showed that the samples were not regular particles of submicron size, and the size of the grains decreased gradually with increasing Pr doping. The experimental data have shown that the samples underwent second order phase transitions near the Curie temperature (Tc). Tc is closest to room temperature at 300 K at a doping level of 0.10. The maximum magnetic entropy change (−∆SMmax) at 5 T is 3.79 (J/kg∙K) (x = 0.15) and the relative cooling power (RCP) is 352.78 (J/kg) (x = 0.15). The results demonstrated that the doping of Pr has an enhanced effect on the performance of the magnetic refrigeration La0.67Sr0.33Mn0.975Co0.025O3 material. This may provide a reference for improving the performance of magnetic refrigeration materials in future research.