Structural and critical properties of Pr0.5Sr0.5MnO3 nanoparticle

Abstract

In this work, a sample of Pr0.5Sr0.5MnO3 nanoparticles with an average crystalline size of <D> = 58 ± 2 nm was prepared by a combination of reactive milling method for 6 h at room temperature and heat treatment at the 1100 °C for 0.5 h. The x-ray diffraction analysis revealed the existence of a Pr0.5Sr0.5MnO3 single phase with the tetragonal structure (I4/mcm space group). Temperature and magnetic field dependences of magnetisation measurements indicated a coexistence of two magnetic phase transitions. One is the antiferromagnetic-ferromagnetic transition at T N = 150 K. The other is the second-order ferromagnetic-paramagnetic phase transition at T C = 273.5 K. Using the modified Arrott plots and the Kouvel-Fisher methods, the critical isotherm analysis, and the scaling relation, the magnetic order in Pr0.5Sr0.5MnO3 nanoparticle sample has been pointed out. Accordingly, the critical exponents were found to be β = 0.486, γ = 1.181, and δ = 3.249. These values are quite close to the allowable exponents of the mean field model, suggesting an existence of the long-range ferromagnetic order. A slight deviation from the mean field model has been explained by the formation of the core/shell structure in Pr0.5Sr0.5MnO3 nanoparticle.