Yttrium doping effect on the structural, morphological and magnetocaloric properties of nanocrystalline Pr_0.7−xY_xBa_0.3MnO₃ (x = 0, 0.05 and 0.1)

We have explored the Yttrium doping effect on the structural, morphological and magnetocaloric properties of nanocrystalline Pr_0.7−xY_xBa_0.3MnO₃ (x = 0, 0.05 and 0.1) compounds synthesized using Sol-gel wet chemical route. The X-ray diffraction pattern analysis has shown that all three samples exhibit orthorhombic crystal structure (space group: Pnma). The Williamson Hall plot procedure was applied to compute crystallite size and lattice strain for the synthesized samples. The temperature dependent magnetic measurements have been carried out in the temperature range from 2 to 300 K with 500 Oe applied external magnetic field. All the studied compounds show ferromagnetic to paramagnetic magnetic phase transition and the transition temperature \(\:\left({T}_{C}\right)\) for these samples are 170 K, 145 K, and 128 K for x = 0, 0.05, and 0.1, respectively. Using Curie-Weiss law the paramagnetic Curie temperature was calculated which came out to be ~ 211 K, 165 K and 162 K for x = 0, 0.05 and 0.1, respectively. The magnetic hysteresis (MH) loop indicates ferromagnetism (FM) at low temperatures (2 K) and linear hysteresis loop belongs to the paramagnetic region at room temperature (300 K). The MH isotherms were measured in 1st quadrant and further the Arrott’s plots were calculated to validate the occurrence of second-order phase transition for all PYBMO compounds. To determine the magnetic entropy change \(\:\left({\varDelta\:S}_{M}\right)\) values, we have used classical Maxwell thermodynamics equation and the applied external magnetic field of 500 Oe. We get the values of \(\:{|\varDelta\:S}_{M}|\:\) around 2.82 J/kg K, 2.49 J/kg K, and 2.24 J/kg K for x = 0, 0.05 and 0.1 samples respectively. Further relative cooling power and refrigerant capacity were calculated for all the samples which is sufficiently high in compared to other similar manganites.