Effects of Zr substitution on structural, morphological, and magnetic properties of bismuth iron oxide phases

Abstract

The present study involves co-precipitation method to grow un-doped and Zr-doped bismuth iron oxide with x Zr = 0.10-0.30. The molar solutions of ferric chloride (FeCl 3 ), zirconyle chloride (ZrOCl 2 ), and bismuth chloride (BiCl 3 ) are prepared in distilled water, and are allowed to react with sodium hydroxide (NaOH). The synthesized powders are then converted into pellets, which are sintered at 500 • C for two hours in a muffle furnace. X-ray diffraction (XRD) shows multi-phase formation in un-doped and Zr doped samples. Scanning electron microscope (SEM) depicts layered structure at low Zr concentration x Zr = 0.10, while uniform surface with smaller grains and voids is observed at x Zr = 0.20, but at x Zr = 0.30, cracks and voids become prominent. The ferromagnetic nature of the un-doped sample is observed by vibrating sample magnetometer (VSM), while paramagnetic behavior appears due to Zr doping. The ferromagnetism in un-doped sample is lost by Zr doping, which is due to the formation of additional Fe-O-Zr bonds that induce paramagnetic behavior.

Biosynthesis of ternary NiCoFe2O4 nanoflowers: investigating their 3D structure and potential use in gene delivery

“…Furthermore, magnetic parameters such as coercivity (Hc) and remanence (Mr) were not detected in this analysis [ 71 – 73 ]. In three-metallic iron NPs, the Fe ions underwent a transformation from iron (III) to iron (II) state due to several factors including the presence of oxygen, particle size, alterations in crystal structure, and ion replacement within the Fe positions, resulting in diminished ferromagnetic behavior [ 74 ]. Figure 7 b illustrates the magnetic behavior of the calcined nanoflowers at 400 °C, at room temperature, subjected to a magnetic field range of -20,000 ≤ H (Oe) ≤ 20,000.…”