Solid State Phenomena Vol. 341

Abstract: This study was carried out to determine the possibility of reducing the iron oxide ratio in silica sand from Ardhumah, an area, (18) km west of Rutba, a city in Al-Anbar Governorate, to obtain sand specifications appropriate for making colorless glasses (not exceeding 0.02 % iron oxide ratio). The reduction process of iron oxide includes three stages; the first stage is magnetic separation to reduce Fe₂O₃ from 0.092% to 0.040%, the second stage is re-floatation which has reduced Fe₂O₃ to 0.024%, finally treatment of the sand output from the first and second stage with diluted HCl or H₂SO₄, this study showed the possibility of obtaining silica sand with a ratio of Fe₂O₃ up to 0.016%.

Abstract: Gallium arsenide (GaAs) nanoparticles' optical and emission properties can be tuned bychanging their size across the visible spectrum. GaAs nanoparticles' optical characteristics aredegraded by oxidation on their surface. This work investigated the optical constants and the opticalband gap for a GaAs nanoparticle immersed in acetone using the laser ablation into liquids (LAL)technique after being exposed to a Nd: YAG pulsed laser operating at the wavelength (1064nm)10Hz frequency, and 7ns pulse width for a fixed flounce of 1.32 J/cm2, and the time of ablationwas 5 minutes. In order to calculate the optical conductivity (σ), refractive index (n), extinctioncoefficient (k), dielectric constant, absorption coefficient (α), and optical band gap, an opticalinvestigation was carried out utilizing a UV-Visible Spectrophotometer region in the wavelengthrange 300-1200 nm. The band gap energy was determined to be 3.8 eV, which is greater than thebulk Ga energy. The band gap energy of nanoparticles increases with increasing laser pulse energyand decreases with increasing pulse repetition rate. Transmission spectra increased as wavelengthsincreased, while optical absorption coefficients, extinction coefficients, and refractive coefficientsdecreased. The difference in optical constants is explained by defect states and the average bandenergy of the system. The acetone stability test reveals a peak at -0.69 mV, indicating low stabilityin nanoparticles.

Abstract: Multilayer sheets or films have many potential applications in micro-nanoelectromechanical systems. When surface and scale effects are not considered, the bending of multilayer film systems can theoretically be discussed by the classical Stoney formula or Timoshenko formula. When the system has anisotropic surface stress or mismatch strain, the four-parameter bending model proposed by Narsu et al. can be used. However, if the thickness of the film is several nanometers and the bending radius of curvature is less than 1micron, the existing theoretical model is no longer applicable. For this reason, a bending formulation for the nanomulti-layer film system is derived and the structure of the multilayer film is optimized in this paper.

Abstract: The rare earth (Eu³⁺ and Tb³⁺) organic complex was doped into PVB matrix materials by solution blending physical method, and the fluorescent composite materials with different concentrations. The analysis indicates that the rare earth organic complexes are evenly distributed in the PVB organic matrix after heating and cooling treatment, and no chemical reaction occurs. The composite exhibits good thermal stability below 150°C; Emission spectrum of Eu complex /PVB films has shown an intense red emission at 615nm with an excitation at 400nm. From the Tb complex /PVB films a green emission at 542nm with an excitation at 254nm has been observed, which provides a new idea for developing fluorescent materials in many fields.