Nanotechnology
Marwa S. Alwazny; Raid A. Ismail; Evan T. Salim
Abstract
In this paper, the optical, structural, and surface morphology of novel lithium-niobate (LN) colloidal synthesis by ablation in liquid using a pulse laser method has been studied and analyzed for the first time. LiNbO3 suspensions are synthesized using a Q-switch Nd-YAG laser with two target types, each ...
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In this paper, the optical, structural, and surface morphology of novel lithium-niobate (LN) colloidal synthesis by ablation in liquid using a pulse laser method has been studied and analyzed for the first time. LiNbO3 suspensions are synthesized using a Q-switch Nd-YAG laser with two target types, each with three different types of liquid environments: deionized water, ethanol, and acetone. The prepared colloidal is to go under further processes to be later used in the photonic application. The optical properties of the suspensions were evaluated by ultraviolet-visible (UV-Visible) measurements. The results showed that the colloidal had a transmission spectrum ranging between 88 to 98% for LN Target and 96 % to 98% for LN Z-cut wafer. The estimated energy gaps are (3.3-3.7 eV) for the prepared target and (4.1-4.3) for the LN Z-cut wafer, which gives good accordance with reported results in the range of ~ 3.7- 4 eV for all samples. In general, the Z-cut wafer target gives better results with ethanol based on optical properties. XRD measurements show the formation of a multi-phase with impurities for a prepared lithium niobate target and multi-phase LiNbO3 films with no impurities or a second phase for another Z-cut wafer. FESEM scan is measured for LiNbO3 films, and the particle size is about 20 and 23 nm.
Materials Science
Farhan A. Mohammed; Evan T. Salim; Azhar I. Hassan; Mohammed H. A. Wahid
Abstract
Using a chemical spray technique, an n-type WO3 polycrystalline thin film was prepared with optimizing parameters (molarity concentration of 80 mM and a substrate temperature of 350 °C). Study the physical properties of WO3 thin film via UV-Visible spectroscopy, XRD, Field Emission-Scanning Electron ...
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Using a chemical spray technique, an n-type WO3 polycrystalline thin film was prepared with optimizing parameters (molarity concentration of 80 mM and a substrate temperature of 350 °C). Study the physical properties of WO3 thin film via UV-Visible spectroscopy, XRD, Field Emission-Scanning Electron Microscope, Energy Dispersive X-ray Spectroscopy, Atomic Force Microscopy, and current-voltage. Tungsten oxide was deposited on glass surfaces at different molarities ranging from 50–90mM. In the UV-Visible spectrum of the WO3 thin film, it was found that the transmittance, reflectivity, and energy gap decreased (78%–53%), (9.63%–5.02%), and (3.40eV–2.63 eV), respectively. The X-ray diffraction of the WO3 film at the optimized was poly-crystalline and had a monoclinic phase, and the preferred orientation (hkl) was 200 at 2 = 24.19. From the image FESEM and EDX, it was found that it has a multi-fibrous network. The average diameter of the fiber is 266 nm, and the ratio of tungsten to oxygen (W/O) is 2.6, with a stoichiometric of 68.6% at the 80 mM concentration. The Atomic Force Microscopy shows that the WO3 thin layer has a nanostructure. The average surface roughness was 5.3 nm, and the Root Mean Square was 8.6 nm. The WO3 film had the lowest resistivity value of 2.393 × 108W cm, and the activation energy was 0.298 eV, among the parameter of the current voltage at substrate temperature and concentration optimum.
