• Bulletin of the Korean Chemical Society
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• v.27 no.2
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• pp.219-223
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• 2006

The thermal decomposition of tetrakis(ethylmethylamido) titanium (TEMAT) has been investigated in Ar and $H_2$ gas atmospheres at gas temperatures of 100-400 ${^{\circ}C}$ by using Fourier Transform infrared spectroscopy (FTIR) as a fundamental study for the chemical vapor deposition (CVD) of titanium nitride (TiN) thin film. The activation energy for the decomposition of TEMAT was estimated to be 10.92 kcal/mol and the reaction order was determined to be the first order. The decomposition behavior of TEMAT was affected by ambient gases. TEMAT was decomposed into the intermediate forms of imine (C=N) compounds in Ar and $H_2$ atmosphere, but additional nitrile (RC$\equiv$N) compound was observed only in $H_2$ atmosphere. The decomposition rate of TEMAT under $H_2$ atmosphere was slower than that in Ar atmosphere, which resulted in the extension of the regime of the surface reaction control in the CVD TiN process.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.1
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• pp.114-118
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• 2011

Dye-Sensitized Solar Cells(DSSCs) consist of a titanium dioxide($TiO_2$) nano film of the photo electrode, dye molecules on the surface of the $TiO_2$ film, an electrolyte layer and a counter electrode. But two transparent conductive oxide(TCO) substrates are estimated to be about 60[%] of the total cost of the DSSCs. Currently novel TCO-less structures have been investigated in order to reduce the cost. In this study, we suggested a TCO-less DSSCs which has titanium double layer electrodes. Titanium double layer electrodes are formed by electron-beam evaporation method. Analytical instruments such as electrochemical impedance spectroscopy, scanning electron microscope were used to evaluate the TCO-less DSSCs. As a result, the proposed structure decreases energy conversion efficiency and short-circuit current density compared with the conventional DSSCs structure with FTO glass, while internal series impedance of TCO-less DSSCs using titanium double layer electrodes decreases by 27[%]. Consequently, the fill factor is improved by 28[%] more than that of the conventional structure.

• Journal of Periodontal and Implant Science
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• v.41 no.6
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• pp.263-272
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• 2011

A number of surface modification techniques using immobilization of biofunctional molecules of Titanium (Ti) for dental implants as well as surface properties of Ti and Ti alloys have been developed. The method using passive surface oxide film on titanium takes advantage of the fact that the surface film on Ti consists mainly of amorphous or low-crystalline and nonstoichiometric $TiO_2$. In another method, the reconstruction of passive films, calcium phosphate naturally forms on Ti and its alloys, which is characteristic of Ti. A third method uses the surface active hydroxyl group. The oxide surface immediately reacts with water molecules and hydroxyl groups are formed. The hydroxyl groups dissociate in aqueous solutions and show acidic and basic properties. Several additional methods are also possible, including surface modification techniques, immobilization of poly(ethylene glycol), and immobilization of biomolecules such as bone morphogenetic protein, peptide, collagen, hydrogel, and gelatin.

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.05a
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• pp.37.1-37.1
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• 2007

• Korean Journal of Materials Research
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• v.17 no.1
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• pp.6-10
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• 2007

In the present study, we investigated the formation of self-organized nanostructure oxide layers on CP Ti and Ti-10Ta-10Nb alloy in an electrolyte of 1M phosphoric acid and 1.5 wt% Hydrofluoric acid. The morphology of oxide film on substrate was observed using scanning electron microscopy and transmission electron microscopy The surface roughness of titanium oxide film was analyzed by atomic force microscopy and the crystalline of specimen was investigated using X-ray diffractometer. The results of this study showed that well-aligned titanium oxide nanotubes are formed with diameter of approx. 100nm and length of approx. 500nm with CP Ti. However, it is clear that TiTaNb alloy highly irregular structure with various diameters. Transmission electron microscope investigations show that the specimens were confirmed as amorphous. Such titanium oxide nanotubes are expected a well-adhered bioacitive surface layer on titanium substrate for orthopedics and dental implants.

• Journal of the Semiconductor & Display Technology
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• v.18 no.1
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• pp.32-37
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• 2019

Titanium dioxide ($TiO_2$) is a promising dielectric material in the semiconductor industry for its high dielectric constant. However, for utilization on Si substrate, $TiO_2$ film meets with a difficulty due to the large leakage currents caused by its small conduction band energy offset from Si substrate. In this study, we propose an in-situ plasma oxidation process in plasma-enhanced atomic layer deposition (PE-ALD) system to form an oxide barrier layer which can reduce the leakage currents from Si substrate to $TiO_2$ film. $TiO_2$ film depositions were followed by the plasma oxidation process using tetrakis(dimethylamino)titanium (TDMAT) as a Ti precursor. In our result, $SiO_2$ layer was successfully introduced by the plasma oxidation process and was used as a barrier layer between the Si substrate and $TiO_2$ film. Metal-oxide-semiconductor ($TiN/TiO_2/P-type$ Si substrate) capacitor with plasma oxidation barrier layer showed improved C-V and I-V characteristics compared to that without the plasma oxidation barrier layer.

• Corrosion Science and Technology
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• v.9 no.4
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• pp.171-174
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• 2010

MAO (micro-arc oxidation) is an eco-friendly convenient and effective technology to deposit high-quality oxide coatings on the surfaces of Ti, Al, Mg and their alloys. The roles of the electrolyte concentration and relative cathode electrode area sizes in the grown oxide film during titanium MAO were investigated. The higher the concentration of the electrolyte, the lower the $R_{total}A$ value. The oxide film produced by the lower concentration of the electrolyte is thinner and less uniform than the film by the higher concentration, which is thick and porous. The cathode area size must be bigger than the anode area size in order to minimize the voltage drop across the cathode. The ratio of the cathode area size to the anode area size must be bigger than 8. Otherwise, the cathode will be another source for voltage drop, which is detrimental to and slows down the oxide growth.

• Korean Journal of Materials Research
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• v.17 no.11
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• pp.593-600
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• 2007

Aluminum was anodized in a $H_2SO_4$ solution, and titanium (IV) oxide ($TiO_2$) was electrodeposited into nanopores of anodic porous alumina in a mixed solution of $TiOSO_4$ and $(COOH)_2$. The photocatalytic activity of the prepared film was analyzed for photodegradation of methylene blue aqueous solution. Consequently, we found it was possible to electrodeposit $TiO_2$ onto anodic porous alumina, and synthesized it into the nanopores by hydrolysis of a titanium complex ion under AC 8-9 V when film thickness was about $15-20{\mu}m$. The photocatalytic activity of $TiO_2$-loaded anodic porous alumina ($TiO_2/Al_2O_3$) at an impressed voltage of 9 V was the highest in every condition, being about 12 times as high as sol-gel $TiO_2$ on anodic porous alumina. The results revealed that anodic porous alumina is effective as a substrate for photocatalytic film and that high-activity $TiO_2$ film can be prepared at low cost.

• Journal of the Korean Society for Heat Treatment
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• v.5 no.1
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• pp.1-12
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• 1992

In order to improve adhesive force of TiN film, we sputtered titanium as interlayer before TiN deposition by Plasma Enhanced Chemical Vapour Deposition. We observed changes of hardness and adhesion at a various thickness of titanium interlayer and also examined analysis. At the critical thickness of the titanium interlayer(about $0.2{\mu}$), adhesive force of TiN films were promoted mostly. But over the critical thickness, a marked reduction of adhesive force was showed, because of the internal stress of titanium interlayer. From AES analysis, the adhesion improvement of TiN films was mainly caused by nitrogen diffusion into titanium interlayer during TiN deposition process which relieved stress concentration at TiN coating-substrate interface.

• Journal of the Korean Society of Clothing and Textiles
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• v.46 no.3
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• pp.530-544
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• 2022

Titanium exhibits substantial corrosion resistance, strength, and ductility, with a specific gravity of approximately 4.5 and a melting point of approximately 1800℃. It is currently used in aircraft parts and space development. This study considered the thermal characteristics, stealth effects of infrared thermal imaging cameras, electromagnetic shielding, and electrical conductivity of Ti-sputtered materials. Base materials of different densities and types were treated using titanium sputtering. Infrared thermal imaging showed a better stealth effect when the titanium layer was directed toward the outside. The film sample presented a better stealth effect than the fabrics did. In each of the samples subjected to titanium sputtering, when the titanium layer was directed outward, the untreated sample or exposed titanium layer showed surface temperatures lower than those of the samples with the titanium layer oriented toward the heat source. Additionally, after the titanium sputtering treatment, the films conducted electricity (low resistance) better than the fabrics did. All titanium-sputtered specimens presented reduced electromagnetic wave transmission and significantly reduced infrared transmission. These results are expected to apply to military uniforms (soldiers' protective clothing to gain the upper hand on the battlefield), medical sensors, multifunctional intelligent textiles and etc.