Probing the effect of Pr doping on the magnetic and magnetocaloric properties of Ba2_xPrxFeMoO6 double perovskites

We report the possible variations in the magnetocaloric properties of Ba2_xPrxFeMoO6 (0.0 < x < 0.4) induced by the controlled substitution of rare earth element Praseodymium (Pr) at the Barium-site in the lattice. Pellets of the double perovskite samples prepared via the conventional solid state reaction method were thoroughly investigated using X-ray diffraction followed by Rietveld analyses that established a cubic crystal structure (Fm 3m) in these samples. The magnetization of the samples was measured as a function of temperature that indicated a single ferromagnetic to paramagnetic phase transition in these materials as the temperature was increased. The Pr doping did not change the crystalline structure but resulted in non-monotonic evolution of the Curie temperature (TC) and decreased magnetization. A second order of magnetic phase transition in these materials was confirmed by the Arrott plots analyses as well as the 'universal master curve method' which indicated the reversible nature of magnetization plus lower hysteresis associated with these materials. Though the Pr doping did not enhance the magnetic entropy change and the relative cooling power yet the near room temperature TC, chemically stable structure, moderate magnetization and tunable magnetocaloric properties of these materials make them attractive for exploration in numerous applications in spintronics and magnetic refrigeration technology.