A comparative study of the effect of the non-magnetic and magnetic trivalent rare-earth ion substitutions on bismuth ferrite properties: Correlation between the crystal structure and physical properties

Abstract

In this paper, the effect of the non-magnetic and magnetic trivalent ion substitutions on structure features and magnetic properties of Bi1-x(Gd or Y)xFe0.95Mn0.05O3 (x = 0.00, 0.01, 0.02, 0.03) nanoparticles have been investigated. The prepared samples were analyzed using the techniques of X-ray diffraction, vibrating sample magnetometer, and scanning electron microscopy (SEM) measurements. Structural analysis of Bi1-x(Gd or Y)xFe0.95Mn0.05O3 nanoparticles shows that a phase transition from rhombohedral (space group R3c) to cubic (space group Pm3¯m) occurs at x=0.02. SEM images show the average particle size of 50–100 nm which decreases with increasing the Gd/Y concentration. The magnetic properties of Gd- and Y-substituted samples such as the coercive field (HC), remanent magnetization (Mr) and saturation magnetization (Ms) indicate a ferrimagnetic behavior compared to the antiferromagnetic behavior of samples BiFeO3 and BiFe0.95Mn0.05O3. The observed magnetic behavior has been attributed to the observed structural phase transition and the reduction of particle size with the substitution of Gd3+ and Y3+ ions.