Synthesis and Characterization of Titanium Oxide Nanomaterials Using Sol-Gel Method
Stotaw Talbachew Hayle,
Girma Goro Gonfa
Issue:
Volume 2, Issue 1, January 2014
Pages:
1-7
Received:
17 December 2013
Published:
30 January 2014
Abstract: This paper reports the effect of temperature on the properties of TiO_2 nanomaterials, synthesis and characterization. TiO2 powders were synthesized by sol-gel method using TiCl4 solution added in deionized water in ice bath under fume hood followed by the addition of ethanol with vigorous stirring for 30 min at room temperature. The gel solution was obtained and then got dried using oven at 200oC for 4 hours. Then, the dried gel was calcinated at 250oC, 400oC and 600oC using furnace for 4 hours each. The synthesized TiO2 nanomaterials were characterized by XRD, UV-Vis spectrophotometer, Transmission electron microscope (TEM), Scanning electron microscope (SEM), Energy dispersive spectroscopy (EDS). XRD shows the particles size with high crystallinity and purity which is in good agreement with the TEM result. The particles size of the synthesized TiO2 nanomaterial at calcination temperatures of 250oC, 400oC and 600oC were 9.22 nm, 14.33 nm and 36.72 nm respectively calculated from XRD result. The absorption edge for TiO2 nanomaterials synthesized by sol gel synthesis method was found to be 350 nm and the corresponding calculated band gap energy was 3.54 eV. The average particles size of the synthesized TiO2 nanopowder investigated from TEM using histograms at calcination temperatures of 250oC, 400oC and 600oC were found (8.55 ± 0.25) nm, (13.82 ± 0.41) nm and (36.06 ± 2.03) nm respectively. The polygonal structure of TiO2 nanomaterials were studied by scanning electron microscope. The EDS result showed that at calcination temperatures of 250oC, 400oC and 600oC, the concentrations of titanium were 33.34%, 32.6% and 31.89%, and the concentrations of chlorine were 2.64%, 0% and 0%, and the concentrations of oxygen were 64.02%, 67.4% and 68.11% in the synthesized TiO2 nanopowder respectively which is qualitatively confirmed by energy dispersive x-ray spectroscopy results.
Abstract: This paper reports the effect of temperature on the properties of TiO_2 nanomaterials, synthesis and characterization. TiO2 powders were synthesized by sol-gel method using TiCl4 solution added in deionized water in ice bath under fume hood followed by the addition of ethanol with vigorous stirring for 30 min at room temperature. The gel solution w...
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Lanthanum Fluoride Charge Trapping Layer with Silicon Nanocrystals for Nonvolatile Memory Device Application
Sheikh Rashel Al Ahmed,
Abu Bakar Md. Ismail
Issue:
Volume 2, Issue 1, January 2014
Pages:
8-12
Received:
5 January 2014
Published:
20 February 2014
Abstract: Silicon nanocrystals (Si-NCs) embedded in a Lanthanum Fluoride (LaF3) insulating layer were fabricated as a charge trapping layer by a simple Chemical Bath Deposition (CBD) technique. The X-Ray diffraction of the deposited layer shows a polycrystalline LaF3 deposition on silicon. The charge storage behavior of Si-NCs embedded in the LaF3 layer have been investigated in metal-insulator-semiconductor (MIS) structures by electrical characterization, where various interface traps and defects were introduced by thermal annealing treatment. The flat-band voltage shift of capacitance-voltage (C–V) and conductance-voltage (G–V) curves of Si: NC-MIS devices were found to exhibit charge trapping. The current-voltage (I–V) measurement also demonstrate that traps have strong influence on the charge storage behavior, in which the traps and defects at the internal/surface of silicon nanocrystals and the interface states at the LaF3 /Si substrate play different roles, respectively. The flat-band voltage (VFB) shift was about 700 mV, which is agreed well enough to capture charge inside the nanoparticle for nonvolatile memory (NVM) device applications. Thickness-dependent flat-band voltage (VFB) shifts in the MIS structure which can be used as a low-voltage nonvolatile memory.
Abstract: Silicon nanocrystals (Si-NCs) embedded in a Lanthanum Fluoride (LaF3) insulating layer were fabricated as a charge trapping layer by a simple Chemical Bath Deposition (CBD) technique. The X-Ray diffraction of the deposited layer shows a polycrystalline LaF3 deposition on silicon. The charge storage behavior of Si-NCs embedded in the LaF3 layer have...
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Concentration-Dependent Optical Properties of Erbium Doped Zirconia Nanocrystals
Timur Sh. Atabaev,
Makio Kurisu,
Kensuke Konishi,
Nguyen Hoa Hong
Issue:
Volume 2, Issue 1, January 2014
Pages:
13-16
Received:
22 January 2014
Published:
28 February 2014
Abstract: This study has investigated the effect of dopant concentration on the luminescent emission of Er3+ in ZrO2 nanocrystals. The structure and morphology of the resulting nanocrystals were characterized by X-ray diffraction and field emission scanning electron microscope. The room-temperature optical properties of synthesized nanocrystals were studied by photoluminescence spectroscopy. The dependence of the luminescence emission on the doping concentration was examined to determine the optimum Er3+ concentration in the samples. Strong luminescence quenching was also observed in samples with high Er3+ concentrations in the ZrO2 host lattice. The luminescent erbium doped zirconia nanocrystals are promising for applications such as fluorescent biomarkers, optical display systems, lamps, etc.
Abstract: This study has investigated the effect of dopant concentration on the luminescent emission of Er3+ in ZrO2 nanocrystals. The structure and morphology of the resulting nanocrystals were characterized by X-ray diffraction and field emission scanning electron microscope. The room-temperature optical properties of synthesized nanocrystals were studied ...
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