Enhancing ferromagnetic properties in bismuth ferrites with non-magnetic Y and Sc co-doping

Abstract

Polycrystalline \({\text{Bi}}_{{1 - x}} {\text{Y}}_{x} {\text{Fe}}_{{0.97}} {\text{Sc}}_{{0.05}} {\text{O}}_{3}\) \((\hbox {x}=0\), 0.06, 0.12; \(\hbox {y}=0.05)\) were prepared by solid-state method by high energy ball milling technique. X-ray diffraction studies confirm polycrystalline nature of the samples with rhombohedral perovskite structure (R3c: Space group). DTA confirms the successfully phase formation in all samples. Room temperature Raman measurements reveal that lattice distortions occur by insertion of Y and Sc at A and B-site of BFO respectively, which may improve the magnetic properties. UV–Visible analysis confirms small band gap tuning in doped BFO resulting in due to the change in Fe–O (bond length) and Fe–O–Fe (bond angle). Room temperature magnetic measurements reveal an improved magnetic properties with saturated magnetization \((M_s = 4.503\hbox { emu/gm})\), remanent magnetization \((M_r = 1.514\hbox { emu/gm})\), coercive field \((H_c = 259.33\hbox { Oe})\) for 12% doping concentration. Co-doping of Y and Sc leads to modification in the spiral modulated spin structure resulting in soft ferromagnetic behavior in contrast to G-type anti-ferromagnetic nature of the parent compound.