Papers by Keyword: Sol-Gel (SG)

Abstract: In the present study, a series of Cu substituted M type Barium hexagonal ferrite BaCuxFe12-xO19 (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) has been synthesized using a Sol- gel auto combustion method. The aim of the present work was to investigate the effects of Cu/Fe ratio on the crystallography and dielectric properties. The XRD studies reveal a formation of the single phase BaFe12O19 at the initial level and mixed phase of S, M and Y hexaferrite at the higher level of copper substitution. The dielectric measurements were carried out at room temperature in a frequency range of 20 Hz to 2MHz. the dielectric constant is found to decrease with the increase of frequency for all the compositions.

Abstract: Organic-inorganic hybrid materials doped with Eu3+, Tb3+ La3+ and lithium ions were produced by sol-gel method using Tetraethyl orthosilicate and poly(methyl methacrylate), ethyl methacrylate, butyl methacrylate, ethyl acetyloacetate as inorganic and organic precursors. Morphology and structure of the hybrids heated at 125°C were characterized by Scanning electron microscopy equipped with Energy dispersive X-ray spectroscopy (SEM/EDS, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), 29Si MAS Nuclear Magnetic Resonance. In all the hybrids, photoluminescence emissions from (5D3), 5D4 →7FJ and 5D0→7FJ transi^{Superscript text}tions of Eu3+ and Tb3+ ions were revealed.

Abstract: The transmission of the femtosecond laser pulses by new biosilicate nanocomposite materials has been experimentally investigated. The strong nonlinear optical properties of these nanocomposite structures have been revealed in spectral characteristics of transmitted ultrashort pulses. The shape of transmitted spectrums through new nanocomposite biomaterials demonstrates major changes indicating the broadening with formation a strong anti Stokes component in the output spectrum with generation of supercontinuum spectra. The carried out studies have showed that the optical nonlinearity of new nanocomposite materials can be regulated by trace amounts of Au or CdS nanoparticles.

Abstract: Spherical carbon nanoparticles were prepared by the polycondensation of resorcinol and formaldehyde using sol-gel method in the presence of cetyltrimethylammonium bromide (CTAB) and subsequent carbonization. Addition of carbon nanotubes (CNTs) in the precursor solution resulted in CNT/carbon porous composites. The effect of carbon nanotubes (CNTs) on the microstructure, pore structure and electrical double layer capacitance of CNT/porous carbon composites was examined based on the field emission scanning electron microscope, transmission electron microscope observation, N2 isothermal adsorption, cyclic voltammetry and charge/discharge tests. The results showed that 20% CNT addition had little effect, but 50% CNT addition significantly changed the microstructure and pore distribution, and charge/discharge properties.

Abstract: The optical and structural properties of Zinc Oxide (ZnO) nanostructures is prepared by sol-gel immersion method at different temperature on Porous Silicon (PSi) Substrates. PSi is produced from the Si by using electrochemical etching process. The ZnO solution is prepared by using the sol-gel immersion method. Parameters such as different deposition time were studied. The optical properties of ZnO Nanostructures will be characterized by using PL and SEM. The structural properties of ZnO Nanostructures will be characterized by using XRD. The result of investigation show that the growth of ZnO nanostructures improving as the deposition temperature increase.

Abstract: Nano-magnesium oxide, MgO film was successfully prepared at various annealing temperatures (400, 450, 500 and 550°C) by using sol-gel method. The behaviour of the MgO as a dielectric layer was investigated in term of its electrical behaviour, relative permittivity and structural properties. The leakage current density obtained was below 10-9 A/cm2 in which is suitable to be used as dielectric layer. Resistivity and relative permittivity values were found to fluctuate with applied annealing temperatures and it was revealed that these changes were related to the surface morphology of the prepared nano-MgO films. Interesting surface morphology was observed for film annealed at 500°C, in which the film formed an island structure, composed of nano particle MgO in range of 45 to 74 nm.

Abstract: Recent research papers for zinc oxide (ZnO) thin films prepared by dip-coating method are reviewed. The aim is on the factors affecting the properties of ZnO thin films prepared by dip-coating method and the preparation of ZnO solution precursor using sol-gel process. Several of journals have been discovered to find out the related study on this topic. It was found that solution chemical equilibrium, substrate and thermal processing are the factors that contribute to the various properties of ZnO thin films. This review hopefully can help in improving the properties of ZnO thin film for possible applications to photoconductor, integrated sensor, transparent conducting oxide electrodes, optoelectronic devices and so on.

Abstract: Atomic Force Microscope (AFM) has been used to study the surface properties of TiO2 nanocoated glass surface at atomic level. TiO2 nanocoated glass surface was prepared by synthesis of titanium butoxide (TTiB) as precursor and was then deposited on glass surface via spin-coating technique. The AFM details studied of TiO2 nanocoated glass surface revealed that the nanoparticle was uniformly distributed throughout glass surface with growth of TiO2 nanostructures below 12 nm via AFM surface morphology and topography characterization, respectively. It was also showed that the cross-sectional view analysis is 5.22 nm and surface roughness, Ra, of coating is 0.858 nm, respectively. The TiO2 nanostructures were successfully seen grew at 0.2 M of sol-gel solution. It confirmed that for the coating application at nanometer scale level on the glass-based material equipment.

Abstract: Preparation of nanohybrid PMMA/TiO2 hybrid was reported by using mixture sol-gel spin coating method. This studied involve modification band gap of TiO2 at different molar concentration of TTiB precursor. AFM image show TiO2 particles encapsulated with PMMA matrix. From UV-Vis spectroscope, we have found as increase of TTiB precursor molar concentration, optical band gap is 3.34 eV, increase in UV-range from 3.25 eV. This study suggested for improvement of optical band gap TiO2 coated glass.

Abstract: Zirconium diboride nano-powders were synthesized by novel sol-gel technology using zirconium oxychloride, boric acid and sucrose as row materials. Different sol network modifiers, such as propylene oxide (PO) and citric acid (CA), were used to control the formation of zirconia precursor sol, respectively. PO could stabilize the sol by protonation and ring-opening reactions, and CA could form the sol network by chelation, then transformed to gel network. Gel was dried, ground, and exposed to carbonthermal reduction heat treatment (1500°C, 2h, flowing 95%argon mix with 5% hydrogen) to prepare ZrB2 nano-powders. In this study, effects of sol network modifiers on preparation procedure, powder characteristics were performed by using Infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Transmission electron microscopy (TEM). The purity of ZrB2 will improve by increasing the molar ratio of B/Zr, the photomicrograph revealed nearly pure ZrB2 nano-powders with spherical shape of 50-200nm and well dispersed were obtained with a molar ratio of B/Zr of 3.0 at 1500°C for 2h using PO as chemical modifier.