Structural and magnetic properties of R0.5Sr0.5Fe0.5Mn0.5O3 (R = Gd, Nd or Pr) perovskites

In this report, we investigate the effect of A-site substitution on the structure and magnetic properties of perovskite compounds R0.5Sr0.5Fe0.5Mn0.5O3 (R = Gd, Nd, or Pr). On Rietveld refinement of the powder X-ray diffraction data, it was seen that Gd0.5Sr0.5Fe0.5Mn0.5O3, Nd0.5Sr0.5Fe0.5Mn0.5O3, and Pr0.5Sr0.5Fe0.5Mn0.5O3 were satisfactorily refined in the orthorhombic space group, Pbnm. We see that substitution at the A-site with rare earth cations of increasing size from Gd, Nd to Pr, leads to decrease in octahedral distortion. This octahedral distortion arises from octahedral tilts and due to the Jahn-Teller distortion afforded by the Mn3+ and Fe4+ ions. Gd0.5Sr0.5Fe0.5Mn0.5O3 exhibits canted antiferromagnetism associated with the Mn3+ spins, observed around 49 K followed by a low temperature antiferromagnetic Gd3+ spin ordering at similar to 3 K. For Nd0.5Sr0.5Fe0.5Mn0.5O3 and Pr0.5Sr0.5Fe0.5Mn0.5O3 samples, a spin glass like nature was observed below 47 K and 58 K respectively. Magnetic nature of all the systems is further characterized by the isothermal field dependent magnetization studies, show the existence of canted antiferromagnetism in Gd0.5Sr0.5Fe0.5Mn0.5O3 and glass like behavior in Nd0.5Sr0.5Fe0.5Mn0.5O3 and Pr0.5Sr0.5Fe0.5Mn0.5O3. The core level X-ray photoelectron spectroscopy (XPS) studies show that a significant amount of the Fe and Mn ions are in + 3 and + 4 oxidation states. (C) 2021 Elsevier B.V. All rights reserved.