Structural, vibrational and surface analysis of Fe3BO6 nanoplates synthesized by combustion method

Abstract

In the present investigation, a simple synthesis method is explored involving a self-combustion of a solid precursor mixture of iron oxide (Fe<inf>2</inf>O<inf>3</inf>) and boric acid (H<inf>3</inf>BO<inf>3</inf>) using camphor (C<inf>10</inf>H<inf>16</inf>O) as fuel in microwave oven in order to form a single phase Fe<inf>3</inf>BO<inf>6</inf> crystallites. An as-prepared ceramic powder in this way after combustion of a precursor, which contained a lot of residual carbon left after the combustion, was reheated at 400 °C to burn it out as oxide in a reaction with air. This is a very simple and fast method to form a phase pure compound from usual metal salts with functional properties. The size and morphology of the Fe<inf>3</inf>BO<inf>6</inf> crystallites has been characterized in terms of X-ray diffraction (XRD) pattern in correlation to the field emission scanning electron microscopy (FESEM) image. A single phase compound Fe<inf>3</inf>BO<inf>6</inf> of an orthorhombic crystal structure with Pnma space group and average crystallites size D = 46 nm is analyzed from the XRD pattern. IR/Raman and X-ray photoelectron spectroscopy (XPS) spectra studied for the Fe<inf>3</inf>BO<inf>6</inf> samples in this investigation elucidate how the density of states of the phonons and valence electrons confine in small crystallites. The XPS bands in Fe3+, B3+ and O2? species and IR/Raman bands in the oxygen polygons confer the results of forming Fe<inf>3</inf>BO<inf>6</inf> with a bonded surface layer. © 2018 Elsevier B.V.