Impact of Pr Doping on the Structural, Magnetic, and Magnetocaloric Properties of La_0.67-xPr_xBa_0.33MnO₃ (x = 0.1 and x = 0.2) Manganites

This report explores the influence of praseodymium (Pr) doping rates on the structural, magnetic, and magnetocaloric properties of La_0.67-xPr_xBa_0.33MnO₃ (x = 0.1 and x = 0.2) manganites synthesized via the sol-gel reaction method. XRD characterization revealed the rhombohedral crystalline structure of our samples with a specific space group. Magnetic analysis demonstrated a paramagnetic-to-ferromagnetic transition in all samples, with this transition intensity increasing with higher Pr³⁺ rates. The measured magnetic isotherms M(T) allowed us to determine Curie temperatures close to T_C = 318 K for x = 0.1 and T_C = 297 K for x = 0.2. Furthermore, M(H) results at a 5-T field for both manganite samples (x = 0.1 and x = 0.2) indicated maximum magnetic entropy changes of 5.80 and 3.5 J·Kg⁻¹·K⁻¹, along with relative cooling powers (RCP) of 440 J·Kg⁻¹ and 280 J·Kg⁻¹, respectively. The magnetic entropy change (− ΔS_M) for these transitions was simulated using a numerical method based on the Landau free energy within the mean-field approximation. The simulation results closely aligned with the experimental findings, demonstrating good agreement for these two transitions.