Abstract
The critical behavior for the second-order ferromagnetic paramagnetic phase transition Ni50Mn29Ga20.8Tb0.2 alloy is studied. The values of the critical exponents were found to be gamma = 1.05, beta = 0.45 and are close to the ones described by the mean-field model. Using the Arrott-Noakes equation of state with these gamma and beta values, the Curie temperature was successfully calculated. The isothermal magnetization M and magnetic entropy change -Delta S-M curves were simulated using the Arrott-Noakes equation, the Landau theory and a mean field model.