Thermal synthesis of Hematite nanoparticles: Structural, magnetic and morphological characterizations

Abstract

Hematite (α-Fe₂O₃) nanoparticle was synthesized using organometallic compound - ferrocene carboxaldehyde through solventless solid state thermal decomposition technique. The crystal structure, magnetic and morphological properties of the decomposed material were studied using powder X-ray diffraction (XRD), superconducting quantum interference device (SQUID) magnetometry, ⁵⁷Fe Mössbauer spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) techniques. Structural study confirmed that the synthesized material is hematite with hexagonal phase and good crystallinity. The temperature-dependent magnetization measurement exhibited the Morin transition - the yardstick for hematite formation. Mössbauer spectroscopic study confirmed the purity of phase of the synthesized material. The SEM study observed mostly the agglomerated tiny particles along with some ring-shaped surface structures. The TEM study of the synthesized material showed that the highest distribution of the particles with ~5 nm size. The observed EDX spectra confirmed the existence of Fe and O in the synthesized material. The solid state reaction process leading to hematite on decomposition of ferrocene carboxaldehyde has also been proposed. Present study describes a simple process for the preparation of pure hematite nanoparticle by solventless method.