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 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Influence of Annealing Temperature on the Properties of ITO Films Prepared by Electron Beam Evaporation and Ion-Assisted Deposition) ผู้เขียน: Artorn Pokaipisit, Mati Horprathum, พิเชษฐ ลิ้มสุวรรณ สื่อสิ่งพิมพ์:pdf AbstractIndium tin oxide (ITO) films were deposited on glass substrates by electron beam evaporation and ion-assisted deposition. Evaporation material source was 90 wt% In2O3 and 10 wt% SnO2 (purity of 99.99%). The ITO films were annealed in the air at 200, 250, 300 and 350 ?C for 1 h. The structures, electrical and optical properties of ITO films were investigated. The deposited films were analyzed by X-ray diffractometer, four-point probe method and UV-NIR spectrophotometer. It was found that the lowest resistivity (2.25 ? 10-4 ?-cm) and highest optical transmittance (83%) of ITO films were obtained at the annealing temperature of 300 ?C. The grain size increased from 36.69 to 46.73 nm with increasing annealing temperature. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : The Color Change of Natural Blue Sapphires by Heat Treatment) ผู้เขียน:Treedej Kittiauchawal, พิเชษฐ ลิ้มสุวรรณ สื่อสิ่งพิมพ์:pdf AbstractThis research aimed to investigate the effects of heat treatment on color and clarity of blue sapphires. The blue sapphires were heated at sequentilly increasing temperature of 1300, 1400, 1500 and 1600 ?C in nitrogen atmosphere. Each temperature, the samples were treated for 12 hours, before and after heat treatment at each temperatures, the color and clarity were measured by spectrophotometer. It was found that, when blue sapphires were heated at high temperatures, the color of the untreated sapphire crystal changed to darker blue at higher temperatures. Whereas, the clarity of all samples were not significantly found in the temperature range of 1300 -1600?C |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : A Biomonitoring Study: Trace Metals in Amusium pleuronectes Shell from the Coastal Area of Chon Buri Province) ผู้เขียน:วิเชียร ศิริพรม, พิเชษฐ ลิ้มสุวรรณ สื่อสิ่งพิมพ์:pdf AbstractThe objective of the present study was to conduct a preliminary investigation of pollution in the coastal area of Chon Buri province environment with a focus on heavy metals in Amusium pleuronectes shell. An energy Dispersive X-ray Fluorescence (EDXRF) spectrometer was used to determine the composition of mineral and levels of the heavy metals, gold (Au), zinc (Zn), lead (Pb), chromium (Cr), iron (Fe) and manganese (Mn) in the Amusium pleuronectes shell. The results showed that the highest to lowest accumulated metals are Fe, Mn, Cr, Zn, Pb and Au, respectively. The crystal structure and microstructure of the shells were studied by x-ray diffraction (XRD) technique and IR spectroscopy, respectively. The XRD patterns and IR spectrum revealed that the samples is made of a mixture phase of aragonite and calcite. In addition, the Electron Spin Resonance Spectroscopy (ESR) was used to study the ions in the samples. It was found that the samples consists of Mn2+ ions in the calcite lattice of the Amusium pleuronectes shell. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Electron Spin Resonance (ESR) and Optical Absorption Spectra of a Manganese Doped Soda-Lime-Silicate Glass System) ผู้เขียน:Nattapon Srisittipokakun, Chittra KedKaew, Jakrapong Kaewkhao, Treedej Kittiauchawal, เขมฤทัย ถามะพัฒน์, พิเชษฐ ลิ้มสุวรรณ สื่อสิ่งพิมพ์:pdf AbstractA (65-x)SiO2:10CaO:25Na2O:xMnO2 glass system with 0 ? x ? 0.5 mol% was prepared and investigated by X-ray diffraction, optical absorption and ESR spectroscopies. The XRD pattern of undoped glass confirmed the formation of an amorphous vitreous structure. The optical absorption spectra exhibited a predominant broad band around 500 nm and its increase was clearly observed from 0.1 mol% of MnO2. This band corresponded to an allowed transition from 5Eg5T2g, of Mn3+ ions. When the MnO2 concentration was increased, the absorption band due to Mn3+ ions dominated. The ESR spectra results exhibited resonance signals at g ? 2.0 with a sextet of hyperfine lines and less intensity at g ? 4.3. The group of hyperfine lines at g ? 2.0 represented Mn2+ ions in octahedral symmetry. However, these lines were broader and disappeared for higher MnO2 concentrations. This behavior indicated the reduction of Mn2+ ions in the glass system as the concentration of MnO2 was increased by increasing the Mn3+ ions. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Effect of Annealed Temperatures on the Morphology of TiO2 Films) ผู้เขียน:วีรนุช แก้ววิเศษ, Wandee Onreabroy, พิเชษฐ ลิ้มสุวรรณ สื่อสิ่งพิมพ์:pdf AbstractTitanium dioxide (TiO2) films were prepared by dip-coating method on the glass slide substrates at room temperature. The TiO2 solution was synthesized from titanium tetraisopropoxide:Ti(OC3H7)4 in isopropanol at molar ratio 1:4. This research focus on the surface and roughness of TiO2 films which were characterized by atomic force microscopy (AFM). In the first experiment, TiO2 films were deposited at 1, 5, 10 and 15 layers and annealed at 500 ?C. Then, the films which were deposited for 15 layers were chosen to be annealed at different temperatures of 300, 350, 400, 450 and 500 ?C. The results showed that, when the number of film layers increased, the grain sizes were clearly observed. The grain size depended on the annealing temperature. It was found that at the temperature of 300 to 500 ?C, the grain sizes were 30-40 nm. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Structures and Optical Properties of TiO2 Thin Films Deposited on Unheated Substrate by DC Reactive Magnetron Sputtering) ผู้เขียน:Nirun Witit-anun, Prasertsak Kasemanankul, Surasing Chaiyakun, พิเชษฐ ลิ้มสุวรรณ สื่อสิ่งพิมพ์:pdf AbstractTitanium dioxide thin films (TiO2) were deposited on unheated substrate on a glass slide and Si-wafer by the DC reactive magnetron sputtering method at different total pressures. The crystal structure, surface morphology and optical transmittance were characterized by X-ray diffractometer, atomic force microscopy and UV-VIS-NIR spectrophotometer, respectively. The deposited films were transparent and the thickness was about 133-168 nm. XRD results showed that all samples possessed a polycrystalline structure and changed from the mixed phase of anatase and rutile, to rutile phases, as the total pressure decreased. An increase in the film’s roughness was observed with increasing sputtering pressure. The optical transmission measurements revealed that the mixed phases of anatase and rutile had higher transmittance than the pure rutile phase. The refractive index, in the visible spectrum was relatively high, while the energy band gap was found to be 3.25 eV. |