A theoretical approach to study the magnetic and magnetocaloric properties in lanthanum manganites

We studied the magnetic and magnetocaloric properties of (La, A)MnO3 (A = divalent metal) compounds on basis of the double-exchange Kubo-Ohata model considering magnetoelastic interactions. The adequacy of the calculations is demonstrated by comparison with experimental magnetization curves for the La0.69Pb0.31MnO3 and La0.75Ca0.25MnO3 compounds. For the case of divalent admixture La2/3(Ca1-xSrx)1/3MnO3 we calculated successfully the isothermal magnetocaloric potential for this series of compounds. Additionally, we showed a correlation between the compressibility and the η-parameter which defines the order of the transition.