Relative Cooling Power of Anderson Lattice Model: An Application to Colossal Magnetoresistive Manganites (Re1-X AX MnO3)

Using a variational method, we studied the field dependence of the magnetocaloric effect, particularly the Relative Cooling Power (RCP) in the magnetic field, of colossally magnetoresistive (CMR) manganites with rare-earth (RE) doping. For the analysis, we considered the materials in the strongly Electron-Lattice Jahn–Teller (JT) coupling region using a two-band (l-b) Anderson Lattice Model Hamiltonian, in a manner similar to two-fluid model approaches coupled with (l-b) hybridization. Along with these materials, we also considered the effect of each of the aforementioned model parameters (local Coulomb repulsion U, large JH coupling in Hund's rule between the eg and t2g spins, and hybridization V between a spin l-polarons and the same spin d-electrons) on the RCP. Our research group has previously applied this variational method to process the field-dependent electronic specific heat C(T) of the doped CMR manganites, and in the case of RCP, we have noted that it is especially sensitive to the magnetic field. Our results show a consistent finding that RCP is directly proportional to the magnetic field parameters, h and m. In this study, RCP is recorded at 407 J/kg at 200 K for h  =  0.05 and m  = 0.5, and at chemical composition levels of x  =  0.3, V  =  0.1, and JH = 1.0. Furthermore, it is noted that our results qualitatively align well with experimental observations.