• Korean Journal of Metals and Materials
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• v.49 no.2
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• pp.153-160
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• 2011

The AISI 216L stainless steel with a composition of Fe-16Cr-6Ni-6Mn-1.7Mo (wt.%) was oxidized at $700{\sim}900^{\circ}C$ in air for 100 h. At $700^{\circ}C$, a thin $Mn_{1.5}Cr_{1.5}O_4$ oxide layer with a thickness of $0.4{\mu}m$ formed. At $800^{\circ}C$, an outer thin $Fe_2O_3$ oxide layer and a thick inner $FeCr_2O_4$ oxide layer with a total thickness of $30{\mu}m$ formed. The non-adherent scale formed at $800^{\circ}C$ was susceptible to cracking. At $900^{\circ}C$, an outer thin $Fe_2O_3$ oxide layer and a thick inner $Mn_{1.5}Cr_{1.5}O_4$ oxide layer formed, whose total thickness was $10{\sim}15{\mu}m$. The scales formed at $900^{\circ}C$ were non-adherent and susceptible to cracking. 216 L stainless steel oxidized faster than 316 L stainless steel, owing to the increment of the Mn content and the decrement of Ni content.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.9
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• pp.31-37
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• 2004

We have proposed a design methodology for large active-area single-mode VCSELS, which have higher reliability and output power, and are well-suited for high-speed operation. The key idea underlying the design methodology is to reduce the effective index difference between active and cladding regions by controlling the thickness and position of the oxide layer. The idea is confirmed by the self-consistent effective index method. By placing the oxide layer position properly, we can increase the radius of the oxide aperture for single-mode operation by 3 times.

• Transactions on Electrical and Electronic Materials
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• v.17 no.4
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• pp.235-237
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• 2016

Oxide/metal/oxide (OMO) thin films were fabricated using amorphous indium-gallium-zinc-oxide (a-IGZO) and an Ag metal layer on a glass substrate at room temperature. The optical and electrical properties of the a-IGZO/Ag/a-IGZO samples changed systemically depending on the thickness of the Ag layer. The transmittance in the visible range tends to decrease as the Ag thickness increases while the resistivity, carrier concentration, and Hall mobility tend to improve. The a-IGZO/Ag (13 nm)/a-IGZO thin film with the optimum Ag thickness showed an average transmittance (T_av) of 71.7%, resistivity of 6.63 × 10⁻⁵ Ω·cm and Hall mobility of 15.22 cm²V⁻¹s⁻¹.

• Journal of Surface Science and Engineering
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• v.47 no.3
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• pp.121-127
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• 2014

In this study, in order to improve corrosion resistance and wear resistance of aluminum, surface treatment was made by anodizing with oxalic acid solution and sealing with nano-diamond powder. Average size of nano-diamond powder was 30nm. Anodizing with oxalic acid made many pores in the aluminum oxide layer. Pore size and oxide thickness were investigated by scanning electron microscope (SEM). Pore size increased as temperature increased and voltage increased. It was possible to make oxide layer with pore diameter more than 50 nm. Oxide thickness increased as temperature and voltage and treatment time increased. Oxide layer with above $10{\mu}m$ thickness was made. Aluminum oxide layer with many pores was sealed by water with nano-diamond powder. Surface morphology was investigated by SEM. After sealing treatment with nano-diamond powder, corrosion resistance, wear resistance and hardness increased.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1489-1496
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• 2009

Amorphous indium-gallium-zinc-oxide thin-film-transistors (TFTs) were modeled successfully. Dependence of TFT characteristics on structure, thickness, and equilibrium electron-density of the active layer was studied. For mono-active-layer TFTs, a thinner active layer had higher field-effect mobility. Threshold voltage showed the smallest absolute value for the 20 nm active-layer. Subthreshold swing showed almost no dependence on active-layer thickness. For the double-active-layer case, better switching performances were obtained for TFTs with bottom active layers with higher equilibrium electron density. TFTs with thinner active layers had higher mobility. Threshold voltage shifted in the minus direction as a function of the increase in the thickness of the layer with higher equilibrium electron-density. Subthreshold swing showed almost no dependence on active-layer structure. These data will be useful in optimizing the structure, the thickness, and the doping ratio of the active layers of oxide-semiconductor TFTs.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.680-686
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• 1995

It has been known that water-side corrosion of fuel rods in nuclear reactor is accompanied with the loss of metallic wall thickness and pickup of hydrogen. This corrosion is one of the important limiting factors ill the operating life of fuel rods. In connection with the fuel cladding corrosion, a device to measure the water-side oxide layer thickness by means of the eddy-current method without destructing the fuel rod was developed by KAERI. The device was installed on the multi-function testing bench in the nondestructive test hot-cell and its calibration was carried out successfully for the standard rod attached with plastic thin films whose thicknesses are predetermined. It shows good precision within about 10% error. And a PWR fuel rod, one of the J-44 assembly discharged from Kori nuclear power plant Unit-2, has been selected for oxide layer thickness measurements. With the result of data analysis, it appeared that the oxide layer thicknesses of Zircaloy cladding vary with the length of the fuel rod, and their thicknesses were compared with those of the destructive test results to confirm the real thicknesses.

• Corrosion Science and Technology
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• v.18 no.6
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• pp.285-291
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• 2019

In this study, the corrosion characteristics of T22 and T92 steel were investigated in 6O₂ + 16CO₂ + 2SO₂ gas environment at 650 ℃. Corrosion characteristics were characterized by weight gain, oxide layer thickness, scanning electron microscope, optical microscope, energy dispersive X-ray spectroscopy, and X-ray diffraction. T22 and T92 steel tended to stagnate oxide layer growth over time. Oxidation kinetics were analyzed using the data of oxide layer thickness, and a regression model was presented. The regression model was significantly acceptable. The corrosion rate between the two steels through the regression model showed significant difference. The T92 steel was approximately twice as large as the time exponent and showed very good corrosion resistance compared to the T22 steel. In both steels, the oxide layer mainly formed a Fe-rich oxide layer composed of hematite (Fe₂O₃), magnetite (Fe₃O₄), and spinel (FeCr₂O₄). Sulfide segregation occurred in the oxide layer due to SO₂ gas. However, the locations of segregation for the T22 and T92 steel were different.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.9
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• pp.121-127
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• 1995

We have analyzed the double insulating layer consisting of anodic oxide and ZnS through TEM experiments. The use of double insulating layer for HgCdTe surface passivation is one of the promising passivation method which has been recently studied deeply and the double insulating layer is formed by the evaporation of ZnS on the top of anodic oxide layer grown in H$_{2}$O$_{2}$ electrolyte. The structure of anodic oxide layer on HgCdTe is amorphous but the structure of oxide layer after the evaporation of ZnS has been changed to micro-crystalline. The interface layer of 150.angs. thickness has been found between ZnS and anodic oxide layer and is estimated to be ZnO layer. The results of analysis on the chemical components of ZnS, the interface layer and anodic oxide layer have showed that Zn has diffused into the anodic oxide layer deeply while Hg has been significantly decreased from HgCdTe bulk to the top of oxide layer. The formation of ZnO interface layer and the change of structure of anodic oxide layer after the evaporation of ZnS are estimated to be defects or to induce the defects which might possibly affect the increase of the positive fixed charges shown in C-V measurements of HgCdTe MIS.

• Journal of Ceramic Processing Research
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• v.22 no.3
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• pp.253-257
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• 2021

Among various thin film encapsulation (TFE) methods, thin films prepared by atomic layer deposition (ALD) have been shown to provide superior protection against the permeation of moisture and oxygen. This technique has numerous of advantages such as excellent uniformity, precise thickness control, and strong adhesion. Therefore, with ozone-based ALD, we conducted the influence of the thickness of aluminum oxide (Al2O3) on moisture barrier properties. From the results of an electrical calcium test, Al2O3 had two distinctly different permeation regimes. Between 10 and 25 nm of Al2O3 thickness, the water vapor transmission rate (WVTR) decreased exponentially from 6.3 × 10-3 to 1.0 × 10-4 g m-2 day-1 (1/60 times). In contrast, as thickness increased from 25 to 100 nm, the WVTR values decreased by only two-thirds, from 1.0 × 10-4 to 6.6 × 10-5 g·m-2·day-1. To better understand the change from an exponential to a sub-exponential regime, defect density and refractive index of Al2O3 were measured. The thickness dependence on defect density and refractive index was analogous with one of moisture barrier performance. These results confirmed the existence of a critical thickness at which the WVTR decreased drastically.

• Tribology and Lubricants
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• v.17 no.6
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• pp.459-466
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• 2001

In this study, the effects of oxide layer formed on the contact parts of TiN coated ball and steel disk on friction characteristics in various sliding conditions were investigated. AISI52100 steel ball was used for the substrate of coated ball specimens, which were prepared by depositing TiN coating with 1(m in coating thickness. AISI1045 steel was used for the disk type counter-body. To investigate the effect of oxide layer on the contact parts of two materials, the tests were performed both in air for forming oxide layer on the contact parts and in nitrogen environment to avoid oxidation. From the test results, the frictional characteristic between the two materials was predominated by iron oxide layer that formed on wear tract of counter-body and this layer caused friction transition and high friction. And the adhesive wear occurred from steel disk to TiN coated ball caused the formation of oxide layer on counter parts between the two materials.