engleski

XRD, Mössbauer spectroscopic and FE SEM characterization of electrospun a-Fe2O3 nanofibres

Recently, a-Fe2O3 (hematite) is recognized as functional material with potential applications in advanced technologies, due to its specific physical and chemical properties. These properties are strongly dependent on the degree of crystallinity, size and shape hematite particles. In addition, some of specific hematite properties can be tailored by doping of a-Fe2O3 with metal ions. Various synthesis methods can be used to produce a-Fe2O3 nanoparticles. In the last two decades, electrospinning received a significant attention of researchers as a simple and effective method for the synthesis of metal oxide nanofibres.1 Generally, the electrospinning uses electric force to draw fibres from viscous polymer solutions containing metal salts or organic compounds. Ceramics metal oxide fibres are then produced by calcination of these as-spunned and dried fibres at elevated temperatures. In the present work the influence of metal (Me) cations (Cr3+ and Ti4+) on the microstructural properties of electrospun a-Fe2O3 nanofibres was investigated. The viscous solutions of PVP polymer (Mw = 1300000) containing corresponding metal salts were used to prepare the raw fibres which were further calcined at 500 or 550 oC to produce a-Fe2O3 or Me-doped a-Fe2O3 fibres. Thus obtained fibres were characterized with XRD, 57Fe Mössbauer, FT-IR, Raman and UV-Vis- NIR spectroscopies as well as FE SEM. The calculated lattice parameters of a-Fe2O3 changed gradually as the concentration of Cr3+ and Ti4+ ions increased thus indicating the formation of solid solutions, a-Fe(2-x)Cr(x)O3 and a-Fe(2-x)Ti(x)O3. The fibres diameter and corresponding architectures depended on the experimental conditions used.

Mössbauer Spectroscopy ; electrospinning ; hematite

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