The effect of temperature on the crystallization of α-Fe2O3 particles from dense β-FeOOH suspensions

• Published in: Materials chemistry and physics Vol. 120; no. 1; pp. 160 - 166
• Main Authors: Zic, M, Ristic, M, Music, S
• Format: Journal Article
• Language: English
• Published: 15-03-2010
• Subjects: Agglomeration; Crystallization; Field emission; Mossbauer spectroscopy; Particle size distribution; Porosity; Scanning electron microscopy; Substructures
• ISSN: 0254-0584
• DOI: 10.1016/j.matchemphys.2009.10.040

The effect of temperature on the crystallisation of alpha-Fe2O3 particles from dense beta-FeOOH suspensions was monitored by 57Fe Mossbauer spectroscopy, XRD, FTIR, field emission SEM, and EDS. Dense suspensions of very long laterally arranged beta-FeOOH fibrils were obtained at 90 C. Crystallisation at 120 C after 18 and 72 h yielded monodisperse alpha-Fe2O3 particles with a shape close to that of a double sphere with an equatorial ring. The particles had two narrow particle size distributions. In these particles a substructure was detected, i.e., the spheres consisted of the linear chains of interconnected alpha-Fe2O3 sub-particles. With increased crystallisation temperature, the increase in the alpha-Fe2O3 particle size and porosity became pronounced. The agglomeration mechanism played an important role in the formation of alpha-Fe2O3 particles.