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 (T-c). 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 (beta=0.246 +/- 0.002, gamma=1.030 +/- 0.018 and (delta=5.069 at T-C=201 K). Whereas for x=0.05 sample, these exponents are close to the mean-field model (beta=0.501 +/- 0.026, gamma=1.007 +/- 0.002 and delta=2.920 at T-C=128 K). These critical exponents fulfill the Widom scaling relation delta=1+gamma/beta, implying the reliability of our values. Based on the critical exponents, the magnetization-field-temperature (M-H-T) data around T-C collapses into two curves obeying the single scaling equation M(H, epsilon) = vertical bar epsilon vertical bar(beta)f(+/-)(H/vertical bar epsilon vertical bar(beta+gamma)) with epsilon =(T-T-C)/T-C is the reduced temperature. (C) 2015 Elsevier B.V. All rights reserved.