scholarly journals Experimental Investigation on the Sputtering Process for Tantalum Oxynitride Thin Films

Photonics ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 53
Author(s):  
Chuan Li ◽  
Jang-Hsing Hsieh ◽  
Y. R. Chuang
Keyword(s):  
Methyl Orange ◽  
Flow Rate ◽  
Nir Spectroscopy ◽  
Oxygen Flow ◽  
X Ray Diffraction ◽  
Effect Analysis ◽  
Continuous Irradiation ◽  
X Ray ◽  
Simulated Solar Light ◽  
Optical Bandgaps

Metal oxynitrides are compounds between nitrides and oxides with a certain level of photocatalytic functions. The purpose of this study is to investigate an appropriate range of oxygen flow rate during sputtering for depositing tantalum oxynitride films. The sputtering process was carried out under fixed nitrogen but variable oxygen flow rates. Post rapid thermal annealing was conducted at 800 °C for 5 min to transform the as-deposited amorphous films into crystalline phases. The material characterizations of annealed films include X-ray diffraction and Raman spectroscopy for identifying crystal structures; scanning electron microscope for examining surface morphology; energy-dispersive X-ray spectroscopy to determine surface elemental compositions; four-point probe and Hall effect analysis to evaluate electrical resistivity; UV-visible-NIR spectroscopy for quantifying optical properties and optical bandgaps. To assess the photocatalytic function of oxynitride films, the degradation of methyl orange in de-ionized water was examined under continuous irradiation by a simulated solar light source for six hours. Results indicate that crystalline tantalum oxynitride films can be obtained if the O2 flow rate is chosen to be 0.25–1.5 sccm along with 10 sccm of N2 and 20 sccm of Ar. In particular, films deposited between 0.25 and 1.5 sccm O2 flow have higher efficiency in photodegradation on methyl orange due to a more comprehensive formation of oxynitrides.

Effects of Reaction Conditions on Deposition of Ferrites from Alkaline Metal Hydroxide Gels

1997 ◽  
Vol 495 ◽  
Author(s):  
Karl F. Schoch ◽  
Theodore R. Vasilow
Keyword(s):  
Flow Rate ◽  
Oxygen Flow Rate ◽  
Oxygen Flow ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Metal Hydroxides ◽  
X Ray ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Mg Content

ABSTRACTFormation of ferrites from aqueous solution of metal salts is a well known process involving precipitation of metal hydroxides followed by oxidation of the resulting gel. The purpose of the present work was to determine the effects oxygen flow rate on the progress of the reaction and on the structure and properties of the resulting precipitate. The reaction was carried out at 70°C with pH of 10.5 and oxygen flow rate of 2,4, or 8 standard liters per hour. The progress of the reaction was monitored by following the oxidation-reduction potential of the solution, which changes dramatically after the Fe(II) is consumed. The reaction rate increased with increasing oxygen flow rate. The Mg content of the precipitate was lower than that of the reaction mixture, possibly because of the pH of the reaction mixture. X-ray diffraction and infrared spectroscopy confirmed formation of a ferrite under these conditions.

Effect of Oxygen Flow Rate on Surface Morphology and Optical Properties of Reactive DC Magnetron Sputtered TiO2 Thin Films

2021 ◽  
Vol 903 ◽  
pp. 51-56
Author(s):  
Lavanya Mekala ◽  
Sunita Ratnam Srirangam ◽  
Rajesh Kumar Borra ◽  
Subba Rao Thota
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Flow Rate ◽  
Oxygen Flow Rate ◽  
Oxygen Flow ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Diffraction Patterns ◽  
Effect Of Oxygen

In the present work, reactive DC magnetron sputtering method is used to deposit TiO2 thin films on glass substrates. The structural, surface morphology and optical studies of TiO2 thin films were discussed by varying the oxygen flow rates from 1 to 4 sccm. X-ray diffraction patterns of TiO2 thin films show amorphous nature. The surface morphological and elemental composition of TiO2 thin films were examined by field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. From the optical absorption spectra, the shifting of absorption edge towards the longer wavelength leads to the decrement of optical bandgap from 3.48 to 3.19 eV with an increase of oxygen flow rate from 1 to 4 sccm.

Effect of Oxygen Flow Rate and Temperature on the Structure of DC Sputtered Nanocrystalline Copper Oxide Films

2007 ◽  
Vol 31 ◽  
pp. 129-131 ◽  
Author(s):  
M.J. Chiang ◽  
C.W. Wu ◽  
H.E. Cheng
Keyword(s):  
Copper Oxide ◽  
Band Gap ◽  
Flow Rate ◽  
Oxide Films ◽  
Oxygen Flow Rate ◽  
Oxygen Flow ◽  
Deposition Condition ◽  
X Ray Diffraction ◽  
Nanocrystalline Copper ◽  
X Ray

Copper oxide, a direct band gap semiconductor with band gap about 1.21-1.51 eV, has been regarded as a promising material for photovoltaic. Nanocrystalline copper oxide films have been synthesized on Si by dc sputtering method. The effects of oxygen flow rate and deposition temperature on the microstructure of nanocrystalline copper oxide films were investigated. X-ray diffraction analysis shows that a broaden peak of Cu2O (111) at 36.720 was observed at the deposition condition of DC power 150 W, pressure 2*10-2 Torr, substrate temperature 100 °C, Ar flow rate 15 sccm and O2 flow rate 1sccm. With increasing the oxygen flow rate to 3 and 5 sccm, CuO (-111) could be observed at 36.58o. The increase of oxygen flow rate resulted in the film formation from Cu2O to CuO. SEM pictures show that copper oxide films exhibit nanosize grains. X-ray diffraction patterns of CuO films deposited at 50~200 °C show that only (-111) plane is obtained. The SEM pictures show that the grain size increases with the deposition increases.

Low-cost thermo-chemical process of TiO2 powder purification: Study of iterative gettering effect

2021 ◽  
Author(s):  
Nesrine Jaouabi ◽  
Wala Medfai ◽  
Marouan Khalifa ◽  
Rabia Zaghouani ◽  
Hatem Ezzaouia
Keyword(s):  
Porous Layer ◽  
Sacrificial Layer ◽  
Low Cost ◽  
Nir Spectroscopy ◽  
Tio2 Powder ◽  
X Ray Diffraction ◽  
X Ray ◽  
Density Reduction ◽  
Transmission Electron ◽  
Layer Effect

The titanium dioxide (TiO2) purity is very important for the TiO2-based applications making essential the impurities density reduction. In this study, we propose an efficient purification process of TiO2 powder in order to reduce impurities. The low-cost proposed approach is based on an iterative gettering (IG) process combining three main steps: (1) a porous TiO2 sacrificial layer formation (p-TiO2), (2) a rapid thermal annealing (RTA) of p-TiO2 powder in an infrared oven at 950°C under air permitting the residual impurities diffusion to the porous layer surface and (3) etching in acid solution to remove the porous layer. Effect of the proposed gettering process on purification efficiency was evaluated by different characterization techniques such as the transmission electron microscopy (TEM), the energy dispersive x-ray spectroscopy (EDX), the UV–Visible-NIR spectroscopy, the X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS). The obtained results showed the efficient removal of metal impurities, such as Cu, Al, P, and Fe confirming the efficiency of the process improving the purity from 89% to 99.96%.

Structural and Optical Characterization of Zinc Telluride Thin Films

2013 ◽  
Vol 665 ◽  
pp. 254-262 ◽  
Author(s):  
J.R. Rathod ◽  
Haresh S. Patel ◽  
K.D. Patel ◽  
V.M. Pathak
Keyword(s):  
Thin Films ◽  
Extinction Coefficient ◽  
Nir Spectroscopy ◽  
Optical Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Evaporation Technique ◽  
Film Form ◽  
Znte Thin Films

Group II-VI compounds have been investigated largely in last two decades due to their interesting optoelectronic properties. ZnTe, a member of this family, possesses a bandgap around 2.26eV. This material is now a day investigated in thin film form due to its potential towards various viable applications. In this paper, the authors report their investigations on the preparation of ZnTe thin films using vacuum evaporation technique and their structural and optical characterizations. The structural characterization, carried out using an X-ray diffraction (XRD) technique shows that ZnTe used in present case possesses a cubic structure. Using the same data, the micro strain and dislocation density were evaluated and found to be around 1.465×10-3lines-m2and 1.639×1015lines/m2respecctively. The optical characterization carried out in UV-VIS-NIR region reveals the fact that band gap of ZnTe is around 2.2eV in present case. In addition to this, it was observed that the value of bandgap decreases as the thickness of films increases. The direct transitions of the carries are involved in ZnTe. Using the data of UV-VIS-NIR spectroscopy, the transmission coefficient and extinction coefficient were also calculated for ZnTe thin films. Besides, the variation of extinction coefficient with wavelength has also been discussed here.

Key Radicals for Hetero-Epitaxial Growth of 3C-SiC on Silicon Substrates

2005 ◽  
Vol 483-485 ◽  
pp. 209-212
Author(s):  
Hideki Shimizu ◽  
Kensaku Hisada ◽  
Yosuke Aoyama
Keyword(s):  
Epitaxial Growth ◽  
Flow Rate ◽  
Hydrogen Plasma ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Ellipsometric Measurement ◽  
X Ray ◽  
Hydrogen Radicals ◽  
Sic Films ◽  
Reflection Electron Diffraction

Effects of the flow rate of C3H8 passed through hydrogen plasma on deposition rates and^microstructures of 3C-SiC films on Si (100) substrate were investigated by a reflection electron diffraction, an X-ray diffraction and an ellipsometric measurement. The deposition rate of the films increased independently of the flow rate of C3H8 with increasing the flow rate of SiH4. The films grown with increasing the flow rate of C3H8 kept single crystalline structure even at high flow rate of SiH4. Hydrogen radicals generated from C3H8 decomposition by plasma increase with increasing the flow rate of C3H8, and play important rolls to keep epitaxial growth.

scholarly journals Preparation of TiO2 nanorods by Sol–Gel template method and measured its photo- catalytic activity for degradation of methyl orange

2019 ◽  
Vol 13 (26) ◽  
pp. 171-177
Author(s):  
Ban M. Al-Shabander
Keyword(s):  
Methyl Orange ◽  
Sol Gel ◽  
Tio2 Nanorods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Photo Catalytic Activity ◽  
Atomic Force ◽  
Degradation Of Methyl Orange ◽  
Titanium Dioxide Nanorods

Titanium dioxide nanorods have been prepared by sol-gel templatemethod. The structural and surface morphology of the TiO2 nanorods wasinvestigated by X-ray diffraction (XRD) and atomic force microscopy(AFM), it was found that the nanorods produced were anatase TiO2 phase.The photocatalytic activity of the TiO2 nanorods was evaluated by thephoto degradation of methyl orange (MO). The relatively higherdegradation efficiency for MO (D%=78.2) was obtained after 6h of exposedto UV irradiation.

scholarly journals A study on preparation and characterization of carbon doped TiO2 nanotubes

2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Srimala Sreekantan ◽  
Roshasnorlyza Hazan ◽  
Zainovia Lockman ◽  
Ishak Mat
Keyword(s):  
Methyl Orange ◽  
Tio2 Nanotubes ◽  
Pure Tio2 ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Methyl Orange Degradation ◽  
Doped Tio2 ◽  
X Ray ◽  
Carbon Doped

The present study is directed to clarify the influence of carbon doping on the degradation of methyl orange. TiO2 nanotubes were prepared by anodizing titanium foils in a two electrode configuration bath with titanium foil as the anode and platinum as the counter electrode. The electrochemical bathconsists of 1 M Na2SO4 with 0.7 g ammonium fluoride, NH4F. The nanotubes obtained were further doped with carbon via in-situ and ex-situ method. Incorporation of carbon on TiO2 via in-situ method is accomplished during the anodization process by introducing oxalic acid into electrolyte while theex-situ doping involves carbon incorporation into pre-fabricated TiO2 nanotube via flame annealing using carbon blackN330. Characterization such as Scanning Electron Microscope (SEM), Energy Dispersive X-ray Analysis (EDX), and X-Ray Diffraction (XRD) are used to determine the surfacemorphology, composition of dopants, and phases exists. Well ordered nanotube with good adherence and smooth surface was obtained for both methods. When the oxide was annealed, X-ray diffraction analysis revealed the presence of anatase and rutile phase. The photocatalytic properties of thepure TiO2 and carbon doped TiO2 were tested for methyl orange degradation and the result indicated that the in-situ doped TiO2 has much better degradation than the ex-situ and pure TiO2. The percentage of methyl orange degradation for in-situ was 20% and 41% higher than ex-situ doped TiO2 and pure TiO2, respectively.

Influence of Ag Doping on the Crystal Structure and Photocatalytic Activity of FeVO4

2011 ◽  
Vol 197-198 ◽  
pp. 919-925 ◽  
Author(s):  
Min Wang ◽  
Qiong Liu
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Photoelectron Spectroscopy ◽  
Methyl Orange Solution ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
X Ray ◽  
Orange Solution ◽  
Decoloration Rate

Silver (Ag+) doped iron (III) vanadate (FeVO4) samples are prepared by the precipitation method and then characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy(XPS). The photocatalytic activity under visible light is evaluated by photocatalytic degradation of methyl orange (MO) in the solution. The results show that both FeVO4 and Ag+ doped FeVO4 samples are triclinic, the later have different surface morphology, and some needle-shaped materials appear in the later. From XPS, there are more Fe2+ ions in Ag+ doped FeVO4 sample than that in FeVO4 one without Ag+. It indicates that Ag+ doping can increase the density of the surface oxygen vacancies of catalysts, which can act as electron traps promoting the electron-hole separation and then increase the photo-activity. The decoloration rate after Ag+ doping against methyl orange solution can reach about 81%, and be more about 20％ than that of pure FeVO4.

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