Tailoring the properties of nanocrystalline multiferroic BiFeO3 by simultaneous substitution of Bi3+ and Fe3+ metal cations for enhanced visible-light-driven photocatalysis.

Multiferroic ceramics (BiFeO₃ ) co doped with Yb and Ni cations (Bi_1–x Yb_x Niy Fe_1–y O₃ ) were synthesized via micro-emulsion route. The dopant (Yb and Ni) contents were fixed x = 0.0 < x >0.125 and y = 0.0 < x >0.25 for six different compositions. The fabricated ceramics were examined with various techniques to index certain features such as crystal habitat, electrical, dielectric, magnetic, and photocatalytic properties. Fourier-transform infrared spectroscopy, X-ray diffraction (XRD), ultraviolet/visible spectroscopy, impedance analyzer constant, current–voltage (I–V) behavior, and vibrating sample magnetometer (VSM). XRD crews revealed a highly crystalline rhombohedral (R3c) structure growth on inclusion of ytterbium and nickel cations in BiFeO₃ ceramics. However, on substituent concentrations, x = 0.125, y = 0.25 moles, the diffraction pattern (111) against 2θ = 27° showed a phase transformation from rhombohedral to orthorhombic phase. Nanocrystalline morsels were harvested with sizes ~21–23 nm. The fabricated ceramics exhibited the resistivity 1.4 × 10⁹ Ω cm^–1. The VSM analysis of fabricated ceramics revealed a notable enhancement of magnetization up to 1.51 emu/g for x = 0.1, y = 0.2 moles. The ceramic composition Bi_0.90Yb_0.10Ni_0.2Fe_0.80O₃ exhibited the minimum optical band gap 1.25 eV, and these particles showed the photocatalytic activity of >64%. The fabricated ceramic inherited magnetic merits and could be easily removed by applying conventional magnetic bar. [ABSTRACT FROM AUTHOR]