Structural and critical behavior near the ferromagnetic-paramagnetic phase transition in La0.6Pr0.1Sr0.3Mn1−xRuxO3 (x = 0.00, 0.05 and 0.15) perovskites

Abstract

The X-ray diffraction were used to investigate the effects of Ru doping on the structural properties of La0.6Pr0.1Sr0.3Mn1−xRuxO3 (x=0.00, 0.05 and 0.15). X-ray diffraction and magnetic measurements were used to investigate the effects of Dy doping on the physical properties of La0.6Pr0.1Sr0.3Mn1−xRuxO3. XRD data were analyzed by Rietveld refinement technique. Results showed that all obtained perovskite manganites were of a single phase type and crystallized in a rhombohedric structure with R3‾c space group. The heat capacity of the manganite La0.6Pr0.1Sr0.3Mn1−xRuxO3 (x=0.00, 0.05 and 0.15) was measured in the temperature range 260–400K. The nature of the ferromagnetic phase transition and the critical exponents of heat capacity near the Curie temperature have been studied. The regulations of variations in the universal critical parameters near the phase transition were established. On the other hand, we used Banerjee’s criteria, modified Arrott plots and the scaling hypothesis to analyze magnetic-field dependence of magnetization near the ferromagnetic–paramagnetic (FM–PM) phase-transition temperature (TC). Experimental results revealed that all samples underwent a second-order phase transition. The estimated critical exponents obtained for x=0.00 sample were close to the 3D Ising model (β=0.321, γ=1.20 and δ=4.75 at TC=360K). Whereas, for a high amount of Ru, these exponents belong to a different universality class and are close to the Heisenberg model (β=0.362, γ=1.32 and δ=4.57 at TC=352K for x=0.05 sample) and (β=0.361, γ=1.33 and δ=4.60 at TC=345K for x=0.15 sample). A detailed analysis and a comparison of the received results obtained with the theoretical predictions and other experimental results were carried out.