Double crystal symmetries and magnetic orderings in co-substituted (Y and Mn) bismuth ferrite

Abstract

The effect of double crystal symmetries on the magnetic property of Bi1-xYxFe1-xMnxO3 has been reported in the present article. The impurity phases (i.e. Bi2Fe4O9, Bi25FeO39 etc.) have been significantly reduced with the co-substitution of Y and Mn in Bi and Fe sites respectively. Rietveld refinement of the X-ray Diffraction patterns reveals the mixed crystal structure of Rhombohedra (R3c space group) as well as Orthorhombic (Pbnm space group) crystallographic symmetry. Percentage of R3c crystal symmetry decreases and Pbnm crystal symmetry increases with the increase in co-substitution of Y and Mn. Peak position in Raman spectra shifts as well as increase the peak broadening with the increase in percentage of co-substitution. It reveals the structural changes in the co-substituted BFO and supports to the XRD analysis. Magnetization has been found to increase with co-substitution and maximum was observed for x = 0.075 compound. A correlation between the crystal symmetries and magnetic property has been established systematically. A phase diagram has been reported by correlating the crystal symmetries and magnetic parameters of co-substituted BFO.