Critical parameters near the ferromagnetic–paramagnetic phase transition in La0.5Ca0.5−xAgxMnO3 compounds (0.1≤x≤0.2)

The critical properties of mixed manganite La0.5Ca0.5 xAgxMnO3 (x = 0.1 and 0.2) around the paramagnetic-ferromagnetic phase transition are investigated through various techniques such as modified Arrott plot, Kouvel-Fisher method, and critical isotherm analysis. The magnetic data analyzed in the critical region using the above methods yield the critical exponents for (x = 0.1) La0.5Ca0.4Ag0.1MnO3 ( =0.311 ± 0.003 and =1.146 ± 0.006 at TC = 226.27 ± 0.02 K). Moreover, the estimated critical exponents of (x = 0.2) La0.5Ca0.3Ag0.2MnO3 are ( = 0.288 ± 0.002 and = 0.948 ± 0.008 at TC = 262.31± 0.06). The values deduced for the critical exponents are closed to the theoretical prediction of 3D-Ising model and tri-critical mean-field model. These results suggest that the present composition should be close to a tricritical point in the La0.5Ca0.5 xAgxMnO3 phase diagram.