Single-phase hematite nanoparticles: Non-alkoxide sol–gel based preparation, modification and characterization

Abstract

In this paper, the uniform hematite (α-Fe2O3) nanoparticles were prepared by a modified Pechini sol–gel method using tartaric acid (TA) and ethylene glycol (EG) as chelating agents. The as-synthesized α-Fe2O3 nanoparticles were calcined at different temperatures including 200, 400, 600, and 800°C for 4h. The as-obtained α-Fe2O3 nanoparticles exhibit a spherical morphology with a particle size of 30–40nm. The nanoparticles were then modified by oleic acid as a capping agent. The final product was characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), and thermal gravimetric analysis (TGA). In addition, the effect of the heat treatment on the particle size and phase evolution was investigated. The vibrating sample magnetometer measurement (VSM) shows that the nanoparticles are ferromagnetic.