C. Kedkaew

Structural and Magnetic Properties of Glass Doped with Iron Oxide

Glasses based on borosilicate system were prepared by melt-quenching method in the composition range of (mol%) 20Na2O : 1.0Al2O3 : 13B2O3 : 6.3CaO : 0.2Sb2O3 : 4.5BaO : (55−X)SiO2 : xFe2O3 (where x = 0, 5, 10, 15, 20 and 25) and the structural, optical and magnetic properties were investigated. The result showed that the density and molar volume of glasses increased with increasing of Fe2O3 concentration. This might be due to an increase of Fe2O3 concentration at the expense of SiO2 caused the opened glass network structure. Fe2O3 also affected the change of B2O3 structure detected by FTIR technique. The magnetic measurement revealed that the glass sample exhibited a ferrimagnetic behavior when doping with 25 % mol Fe2O3.

Properties of CoO doped in Glasses Prepared from Rice Hush Fly Ash in Thailand

In this work, properties of glass from local rice husk ash (RHA) in Thailand have been investigated. RHA was sintered in different temperature. Compositions and phases of RHA were analyzed by energy dispersive x-ray fluorescence spectrometer (EDXRF) and X-ray diffractometer (XRD). The glasses were melt from RHA in formula 20 Na2O : 1.0 Al2O3 : 13 B2O3 : 6.3 CaO : 0.2 Sb2O3 : 4.5 BaO : 55SiO2 (using RHA as a SiO2 source) The density values of all RHA glasses are comparable and larger than glass from pure SiO2 under same glass formula and preparing condition. These results are corresponding with refractive index values. The RHA glasses showing colorless with absorption edge in ultraviolet region were obtained. The dark blue color glasses were melted from RHA with different CoO concentration. From this part, not found to be the relation of density and refractive index of glass with CoO concentration in glass matrix. From absorption spectra, the absorption peak were appeared around 600 nm, and peak intensity are increased, with increase CoO, correspond to 4A2(4F) → 4T1(4P) state of Co2+ in tetrahedral symmetry.

Influence of Ni Doping on Structural, Morphological and Optical Properties of Sol-Gel ZnO Thin Films

Ni-doped ZnO thin films were prepared on glass slide substrates by a sol-gel dip coating method with different Ni doping concentrations (0-33 mol%). The effect of Ni doping concentration on structural, surface morphology and optical properties of the thin films was characterized by XRD, FESEM and UV-Vis spectrophotometer. The XRD results indicated that pure ZnO thin film exhibited a hexagonal wurtzite structure. Ni (OH)2 phase were observed at a high Ni doping concentration. The FESEM images showed that the surface morphology and surface roughness were sensitive to the Ni doping concentration. The optical transmission measurements were observed that the transmittance decreased with increasing the Ni doping concentration.

Spectral Investigations of Dy3+-Doped Gd2O3-CaO-P2O5 Glasses

Dy3+-doped phosphate glasses of the compositions 20Gd2O3 : 10CaO : (70-x)P2O5 : xDy2O3, where x = 0.05, 0.10, 0.50, 1.00 and 1.50 mol% have been prepared by melt quenching technique and characterized by optical absorption, emission spectra and decay curve analysis. All the transitions in the absorption spectra are originated from the 6H15/2 ground level to the various excited states and these are intra configuration (f-f) transitions. The observed twelve absorption bands centered at 349, 362, 387, 425, 451, 473, 750, 800, 895, 1089, 1266 and 1676 nm are assigned to 6P7/2, 4P3/2, 4F7/2, 4G11/2, 4I15/2, 4F9/2, 6F3/2, 6F5/2, 6F7/2, 6F9/2, 6H9/2 and 6H11/2 transitions, respectively. The absorption spectra of glasses increase with increase in Dy3+ ion concentrations. The emission spectra of Dy3+-doped glasses are observed to be centered at 483, 573, 662 and 752 nm originated from the 4F9/2→6H15/2, 4F9/2→6H13/2, 4F9/2→6H11/2 and 4F9/2→6H9/2 transitions, respectively under excitation at 349 nm. The highest emission intensity of Dy3+-doped glass is 0.50 mol% due to concentration quenching effect. The experimental lifetimes are found to decrease when Dy3+ ion concentrations increased due to energy transfer process between Dy3+ ions.

Optical and Physics Investigation of Fe2O3 Doped in Soda-Lime Silicate Glass at Different Melting Temperature

In this work, the effects of melting temperature (1200, 1300, 1400 and 1500 °C) on glass properties, prepared in the composition 64.4SiO2: 10.0CaO: 25.0Na2O: 0.6Fe2O3 have been investigated. The Fe2O3 doped glass shown green color due to the homogeneous distribution of Fe3+ and Fe2+ ions in the glass matrices. Refractive index, dielectric constant, optical dielectric constant and the reflection loss increases when the melting temperature is increased. The absorption bands are observed in the all spectra with the peaks around 380 and 435 nm are attributed to Fe3+ and board peak around 1,050 nm due to Fe2+. The Fe2+ peaks are increased with increasing of melting temperature, correspond with glass color.

Coloration in Soda-Lime-Silicate Glass System Containing Manganese

The UV-visible spectra of soda-lime-silicate glass system with the base composition (65-x) SiO2: 10CaO: 25Na2O: xMnO2 % mol, (where x is 0.0, 0.02, 0.05, 0.10, 0.30 and 0.50 %mol) were studied at room temperature. The results are shown that the colors of glass samples were altered from colorless to dark purple with increasing of MnO2 concentration and were stable at room temperature. The color of glass sample with 0.3 %mol MnO2 was purple. Moreover, it has been found that the density and refractive index were contiguous. The optical absorption spectra can be confirmed the color of these glass samples. They exhibited a predominant broadband around 500 nm and it was clearly observed, its increasing since 0.1 %mol of MnO2. This band corresponds to an allowed transition from 5Eg5T2g, which attributed to Mn3+. When increasing MnO2 concentration, the absorption band due to Mn3+ ion was dominating.

Investigated on Photoluminescence Properties of Sm3+ Ions in Gadolinium Calcium Phosphate Glasses

Sm3+-doped gadolinium calcium phosphate glasses of the composition (70-x)P2O5 : 10CaO : 20Gd2O3 : xSm2O3 (PCGSm), where x = 0.05, 0.10, 0.50, 1.00, 1.50, 2.00, 2.50 and 3.00 mol% have been prepared by melt-quenching technique and investigated their photoluminescence properties. The emission spectra of Eu3+-doped glasses recorded in wavelength range 500-750 nm with 402 nm excitation. All the spectra exhibited 4 emission bands corresponding to the 4G5/2→6H5/2, 4G5/2→6H7/2, 4G5/2→6H9/2 and 4G5/2→6H11/2 transition, respectively. The peak intensities increase with the increase of concentration from 0.05 to 0.5 mol% and beyond that the quenching in the emission peak intensities have been observed.

Effect of Annealing Temperature on NiO/ZnO Heterojunction Thin Films Prepared by Sol-Gel Method

In this research, NiO/ZnO heterojunction thin films were fabricated on a ITO substrate by a sol–gel technique. The as-prepared thin films were annealed at various temperatures. The effect of annealing temperature on structural, surface morphology and electrical properties of thin films was investigated by XRD, FESEM and I-V characteristic measurement. The XRD results revealed that NiO/ZnO thin film was polycrystalline and exhibited better crystallization when annealing temperature was increased. The current-voltage curve of all sample exhibited the diode behaviour.