Magnetocaloric properties and critical behavior in double perovskite RE₂CrMnO₆ (RE = La, Pr, and Nd) compounds

Magnetocaloric effect (MCE) is a thermodynamic response of the coupling effect between the magnetic sub-lattice(s) with applied magnetic fields, which is strongly correlated with the corresponding magnetic transition. In this work, the magnetic properties, magnetic phase transition, MCE and critical behavior of the paramagnetic (PM) to ferromagnetic (FM) transition in double perovskite RE₂CrMnO₆ (RE = La, Pr, and Nd) compounds are investigated. The double perovskite compounds reveal a second-ordered magnetic phase transition around T_C of 112, 93, and 80 K for RE of La, Pr, and Nd, respectively. The corresponding values of peak magnetic entropy change (-ΔS_M^max) around T_C are 1.31, 1.86, and 2.23 J kg⁻¹K⁻¹ under the ΔH of 0–7 T. Moreover, the critical exponent study was conducted to probe the nature of critical behavior around the PM to FM transition by the modified Arrott plot (MAP), Kouvel-Fisher (K–F), ΔH dependence of -ΔS_M^max, and universal scaling hypothesis methods. The evaluated reliable critical exponents (β, γ, and δ) data for RE₂CrMnO₆ (RE = La, Pr, and Nd) follows the mean-field theory model, proving the existence of long-range FM orders in these double-perovskite oxide compounds.