Structural, magnetic, magnetocaloric properties and the critical exponents of La0.9 0.1MnO2.95 synthesized using the sol–gel method were investigated in this research paper. This compound crystallizes in the rhombohedral system with \(\text{R}\overline{3}\text{c }\) space group, and no secondary phases were detected. The variation of the magnetization as a function of temperature revealed a transition from the paramagnetic to ferromagnetic near the Curie temperature TC (TC = 227 K) with an additional peak observed between T = 260–300 K. The Arrot plot depicted a positive slope corraborating the second order transition. The magnetic entropy change obtained departing from the isotherm magnetization curves demonstrated a maximum around TC equal to 1.95 J Kg−1 K−1 when the magnetic field is equal to 2 T. The relative cooling power at 2 T proved to be 121.28 JKg−1. La0.9 0.1MnO2.95 can therefore be regarded as an outstanding candidate for magnetic refrigeration. In order to explore the transition nature of the compound, critical exponents are used. Several methods including modified Arrot plots, the Kouvel-Fisher method and Widom scaling were applied to determine the critical exponents β, γ, δ and the Curie temperature TC. The obtained values for these parameters β, γ and δ were compared to literature values derived from such models as the tricritical model, 3D Heisenberg model and the Ising model. The obtained results yielded that the critical exponents of Heisenberg model are satisfactory, which puts into evidence short range-interactions accounted for by the decrease of the crystallite size.
