Critical behavior near the ferromagnetic-paramagnetic phase transition temperature of Pr0.67Ba0.33Mn1−xFexO3 (x=0 and 0.05) manganite

Critical behavior of Pr0.67Ba0.33Mn1−xFexO3 (x=0 and 0.05) perovskite-manganites is studied around their Curie temperatures (TC). Results reveal that the two samples undergo a second-order phase transition. The estimated critical exponents obtained for x=0 sample are close to the tricritical mean-field model (β=0.246±0.002, γ=1.030±0.018 and δ=5.069 at TC=201 K). Whereas for x=0.05 sample, these exponents are close to the mean-field model (β=0.501±0.026, γ=1.007±0.002 and δ=2.920 at TC=128 K). These critical exponents fulfill the Widom scaling relation δ=1+γ/β, implying the reliability of our values. Based on the critical exponents, the magnetization-field-temperature (M-H-T) data around TC collapses into two curves obeying the single scaling equation M(H,ε)=|ε|βf±(H/|ε|β+γ) with ε=(T-TC)/TC is the reduced temperature.