Effect of Ti substitution on the critical behavior around the paramagnetic-ferromagnetic phase transition of Pr0.75Bi0.05Sr0.1Ba0.1Mn1-xTixO3 (x=0, 0.02 and 0.04) perovskite compounds

Abstract

In this research work, our central focus is upon the investigation of the effect of the substitution of non magnetic Ti ions on the critical behavior of Pr0.75Bi0.05Sr0.1Ba0.1Mn1-xTixO3 (x = 0, 0.02 and 0.04) manganites. All our compounds underwent a second-order paramagnetic to ferromagnetic transition as temperature decreases. Several techniques such as modified Arrott plots, Kouvel-Fisher analysis and critical isotherm method were used in order to determine the values of the critical exponents β, γ and δ as well as the accurate Curie temperature TC. The obtained values were found to be close to the 3D-Heisenberg model for the parent compound indicating a short-range inhomogeneous magnetic exchange coupling and to the mean-field model for doped samples describing long-range exchange interactions. We have also demonstrated that the universality class of the studied manganites was affected by Ti-doping. Besides, we highlighted that these parameters follow scaling equation with the magnetization data scaled into two different curves below and above TC confirming that the determined critical exponents and TC are reasonably accurate.