Preparation by a simple route and characterization of amorphous and crystalline Fe2O3 nanophases

A simple microwave assisted solvothermal route has been developed to prepare amorphous (γ-) and crystalline (ε-, β- and α-) Fe2O3 nanophases. The prepared nanophases have been characterized chemically, structurally, optically and magnetically by the available methods like thermogravimetric and differential scanning calorimetric analyses, X-ray powder diffraction analysis, scanning electron microscopic and transmission electron microscopic analyses, energy dispersive X-ray spectroscopic and UV–visible spectral analyses, and vibrating sample magnetometric measurements. The average particle sizes obtained through transmission electron microscopic analysis are 19, 24, 29 and 33 nm respectively for the γ-, ε-, β- and α-Fe2O3 phases. Results obtained in the present study indicate that the method adopted is an effective one for preparing the γ-, ε-, β- and α-Fe2O3 nanophases with good purity, stoichiometry, homogeneity, and optical and magnetic properties.

► The γ- , ε-, β- and α- Fe2O3 nanophases have been prepared successfully by a simple solvothermal method along with calcination.
► The optical absorption edges are red-shifted.
► The as-prepared phase is found to exhibit superparamagnetism.
► The calcined phases are found to exhibit weak ferromagnetism.