Using variational method, we studied the field dependence of magnetocaloric properties, specifically magnetic entropy change (−ΔSM) and relative cooling power (RCP), in rare earth manganites doped with alkaline earth elements. The studied compounds, Re1−X AX MnO3, where Re represents La, Pr, or Nd and A denotes Ca, Sr, or Ba, etc., exhibit Colossal Magnetoresistance (CMR). Analysis utilized a two-band (ℓ-b) Anderson Lattice Model Hamiltonian to investigate these materials within the strong electron-lattice Jahn–Teller (JT) coupling regime and (ℓ-b) hybridization. From our results, we find that the magnetic entropy change (−ΔSM) increases with increasing temperature for a particular value of magnetic field ‘h’ and ‘m’ parameters showing the sharp peak at low temperature and finally decreases at higher temperatures. The sharpness of the peak increases with increasing the ‘h’ and ‘m’ values. In the present study, −ΔSM reaches a peak value of about 1.4 J/Kg K and the corresponding RCP peak value of 407 J/Kg at temperature Tc ~ 200 K for magnetic field parameters ‘h’ = 0.05 and ‘m’ = 0.5 with doping x = 0.3, V = 0.1 and JH = 1.0. It is seen that our results are in good agreement with the experimental results.
