Synthesis, structural and magnetic behavior and theoretical approach to study the magnetic and magnetocaloric properties of the half-doped perovskite Nd_0.5Ba_0.5CoO₃

In the current research work, half-doped perovskite cobaltite Nd_0.5Ba_0.5CoO₃ (NBCO) was prepared by the sol–gel process. We study the structural, morphological, magnetocaloric and magnetic properties of NBCO. The X-ray diffraction patterns showed that the NBCO sample crystallizes in the orthorhombic distorted symmetry with the Pmmm space group. Magnetic measurements indicated the existence of a paramagnetic (PM)–ferromagnetic (FM) transition at T_C = 125 K. A ferromagnetic-to-antiferromagnetic transition is observed at T = 25 K. The second-order transition was confirmed by both Banerjee criterion and construction of the universal curve. Indeed, the magnetic entropy change (-ΔS_M) value estimated by Landau and Hamad theories is close to that obtained using the classical Maxwell relation. The value of the relative cooling power (RCP) under a magnetic field of 5 T is 114 J. kg⁻¹; therefore, this compound can be considered as a potential candidate for application in the field of magnetic refrigeration.