Critical parameters near the ferromagnetic-paramagnetic phase transition in La0.67−xYxBa0.23Ca0.1MnO3 compounds (x=0.10 and x=0.15)

The critical properties of the mixed manganite La0.67−xYxBa0.23Ca0.1MnO3 with x=0.10 and x=0.15 around the paramagnetic (PM)-ferromagnetic (FM) phase transition were investigated through various techniques. These involved modified Arrott plots, Kouvel-Fisher method and Widom scaling relation. Magnetic data, analyzed in the critical region, using the above methods, yielded the critical exponents for (x=0.10) La0.57Y0.10Ba0.23Ca0.1MnO3 (β=0.312±0.002 and γ=1.147±0.003 at TC=299.23±0.05 K). Moreover, the estimated critical exponents of (x=0.15) La0.52Y0.15Ba0.23Ca0.1MnO3 were β=0.286±0.004 and γ=0.943±0.002 at TC=289.53±0.06 K. The critical exponents' values were close to the theoretical values of 3D-Ising model and tricritical mean-field model. These results suggested that the present composition should be close to a tricritical point in the La0.67−xYxBa0.23Ca0.1MnO3 phase diagram. Expressing the field dependence as ΔSM∝Hn allowed us to establish a relationship between the exponent n and the critical exponents of the material and to propose a phenomenological universal curve for the field dependence of ΔSM.

Graphical AbstractScaling plots indicating two universal curves below and above TC for La0.57Y0.10Ba0.23Ca0.1MnO3 (Inset show the same plots on a log-log scale)Figure optionsDownload as PowerPoint slide