Faculty Publications
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Item Structural, vibrational and surface analysis of Fe3BO6 nanoplates synthesized by combustion method(Elsevier B.V., 2018) Kumari, K.In the present investigation, a simple synthesis method is explored involving a self-combustion of a solid precursor mixture of iron oxide (Fe2O3) and boric acid (H3BO3) using camphor (C10H16O) as fuel in microwave oven in order to form a single phase Fe3BO6 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 Fe3BO6 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 Fe3BO6 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 Fe3BO6 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 Fe3BO6 with a bonded surface layer. © 2018 Elsevier B.V.Item Phase analysis, FTIR/Raman, and optical properties of Fe3BO6 nanocrystallites prepared by glass route at moderate temperature in ambient air(Elsevier B.V., 2018) Kumari, K.In this paper, a facile synthesis method is explored from a supercooled liquid Fe2O3–B2O3 precursor using microwave furnace in order to obtain a single phase Fe3BO6 compound. Study includes X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM), high resolution transmission electron microscopy (HRTEM) images, FTIR/Raman and optical property of sample. The crystal structure and size of the Fe3BO6 crystallites have been characterized in terms of XRD pattern in correlation to the FESEM/HRTEM images. A single phase compound Fe3BO6 of an orthorhombic crystal structure with Pnma space group and average crystallites size D = 49 nm is analyzed from the XRD pattern. IR and Raman bands in the oxygen polygons confer the results of forming Fe3BO6 with a bonded surface layer. UV–visible absorption spectrum over a spectral range 200–800 nm of wavelengths reveals two high-energy bands 222 and 277 nm possibly represent a ligand to metal charge transfer transition while one broad and relatively weak band appears in the visible region at 400 nm ascribed to a ligand field transition 6A1 ? 4T1 of the 3 d5 electrons in the Fe3+ ions occupied. This compound also endures good optical properties in the visible and ultraviolet regions that can be combined to magnetic and other properties useful for developing multifunctional features for possible applications. © 2018Item Synthesis and characterization of zinc oxide incorporated iron borate glass-ceramic(Elsevier Ltd, 2019) Ramteke, R.; Kumari, K.; Bhattacharya, S.; Rahman, M.R.Here, zinc oxide (ZnO) incorporated iron borate (Fe3BO6) glass-ceramics have been synthesized using the traditional melt-quenching technique, and the role of ZnO has been investigated. X-ray diffraction (XRD) and scanning electron microscopy (SEM) reveals that the prepared samples have a single crystalline phase and crystalline nanostructures, respectively. The orthorhombic crystal structure has been retained without the formation of a new crystalline phase. The addition of ZnO is found to distort the Fe3BO6 lattice by substituting Zn2+ in the Fe3+ sites, with the formation of ZnO6 structural units as revealed by Fourier transform infrared spectroscopy (FTIR). FTIR and Raman spectroscopy conducted to study the structure of glass-ceramic, have also revealed the formation of other structural units like ZnO4, BO3, BO4, and FeO6 in the system. Surface analysis conducted by X-ray photoelectron spectroscopy (XPS) reveals that the addition of ZnO diminishes the formation of surface B2O3 layer which forms over the Fe3BO6 phase in the Fe3BO6 iron borate glass-ceramic system. ZnO addition has also shown a remarkable difference in the volume of the crystallization in the system, thereby paving the way for controlled crystallization in the iron borate glass-ceramic system. The controlled crystallization was achieved through additive content, retaining the iron borate (Fe3BO6) glass-ceramic system without the evolution of any secondary phases even with large additive concentrations up to 10 mol%. © 2019 Elsevier B.V.