• Journal of Powder Materials
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• v.20 no.6
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• pp.460-466
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• 2013

4 mol% Yttria-stabilized zirconia (4YSZ) coatings with $200{\mu}m$ thick are fabricated by Electron Beam Physical Vapor Deposition (EB-PVD) for thermal barrier coating (TBC). $150{\mu}m$ of NiCrAlY based bond coat is prepared by conventional APS (Air Plasma Spray) method on the NiCrCoAl alloy substrate before deposition of top coating. 4 mol% YSZ top coating shows typical tetragonal phase and columnar structure due to vapor phase deposition process. The adhesion strength of coating is measured about 40 MPa. There is no delamination or cracking of coatings after thermal cyclic fatigue and shock test at $850^{\circ}C$.

• JSTS:Journal of Semiconductor Technology and Science
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• v.3 no.1
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• pp.1-12
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• 2003

This paper describes a study on the abnormal behavior of the electrical characteristics of the (n)GaAs/Ti/Pt/Au Schottky contacts prepared by the two techniques of electron beam deposition and rf sputtering and after an annealing treatment. The samples were characterized by I-V and C-V measurements carried out over the temperature range of 150 - 350 K both in the as prepared state and after a 300 C, 30 min. anneal step. The variation of ideality factor with forward bias, the variation of ideality factor and barrier height with temperature and the difference between the capacitance barrier and current barrier show the presence of a thin interfacial oxide layer along with barrier height inhomogenieties at the metal/semiconductor interface. This barrier height inhomogeneity model also explains the lower barrier height for the sputtered samples to be due to the presence of low barrier height patches produced because of high plasma energy. After the annealing step the contacts prepared by electron beam have the highest typical current barrier height of 0.85 eV and capacitance barrier height of 0.86 eV whereas those prepared by sputtering (at the highest power studied) have the lowest typical current barrier height of 0.67 eV and capacitance barrier height of 0.78 eV.

• Journal of the Korean Graphic Arts Communication Society
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• v.18 no.1
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• pp.47-58
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• 2000

Transmittances of SiO2 and ZrO2 thin films, made by the electron beam evaporation method, were measured with a spectrophotometer to be used in determining their optical constants and thicknesses in the envelop method. New color glass lenses with high transmittance, which now can be manufactured in the industry, was successfully designed by using these constants. Also the vacuum evaporator could be mechanically corrected with these constants as correction factors.

• Ceramist
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• v.9 no.6
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• pp.24-29
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• 2006

Electron beam physical vapor deposition (EB-PVD) process has currently been applied to thermal barrier coatings (TBCs) for aircraft engines. Due to unique columnar structure, EB-PVD TBCs have advantages in resistances to thermal shock and thermal cycle for their applications, compared to films prepared by plasma spray By the EB-PVD equipment, we successfully obtained yttria-stabilized zirconia (YSZ) layer which has columnar and feather like structure including a large amount of nano size pores and gaps. The EB-PVD technique has been developed for coating functional perovskite type oxides such as (La, Sr)MnO3. Electrode properties have been improved by interface and structural control.

• Journal of the Korean Ceramic Society
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• v.41 no.5
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• pp.364-369
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• 2004

The barrier and optical properties of AlO$_{x}$ thin films on polycarbonate deposited by Reactive Ion Beam Sputtering (RIBS) were investigated at different oxygen partial pressure. We measured the deposition rate of AlO$_{x}$ thin films. As the oxygen partial pres-sure increased, the deposition rate increased then decreased. The changes of deposition rate are associated with the properties of deposited films. The properties of deposited AlO$_{x}$ thin films were studied using X-ray Photoelectron Spectroscopy (XPS), Scan-ning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM). Optimum deposition parameters were found for fabricat-ing aluminum oxide thin films with high optical transparency for visible light and low Oxygen Transmission Rate (OTR). The optical transmittance of AlO$_{x}$ thin film deposited on polycarbonate (PC) showed the same value of bare PC.bare PC.

• Proceedings of the Materials Research Society of Korea Conference
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• 1994.11a
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• pp.24-24
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• 1994

• Journal of the Korean Vacuum Society
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• v.4 no.S2
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• pp.163-169
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• 1995

Ion beam assisted deposition(IBAD) technique was used to synthesize hard coatings including diamond-like carbon(DLC), carbon nitride(CN) and metal-ceramic multilayered films. It was found that DLC films formed at low energy ion bombardment possess more $Sp^3$ bonds and much higher hardness. The films exhibited an excellent wear resistance. Nanometer multialyered Fe/TiC films was deposited by ion beam sputtering. The structure and properties were strongly dependent on the thickness of the individual layers and modulation wave length. It was disclosed that both hardness and toughness of the films could be enhanced by adjusting the deposition parameters. The CN films synthesized by IBAD method consisted of tiny crystallites dispersed in amorphous matrix, which were identified by electron diffraction pattern to be $\beta -C_3N_4$.

• Journal of the Korean Society for Heat Treatment
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• v.23 no.1
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• pp.29-33
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• 2010

Titanium nitride (TiN) films were deposited on the polycarbonate substrate by using radio frequency (RF) magnetron sputtering without intentional substrate heating. After deposition, the films were bombarded with intense electron beam for 20 minutes. The intense electron irradiation impacts on the crystalline, hardness and surface roughness of the TiN films. The films irradiated with an electron beam of 300 eV show the small grains on the surface, while as deposited TiN films did not showany grains on the surface. Also the surface harness evaluated with micro indenter was increased up to 18 Gpa at electron energy of 900 eV after electron beam irradiation. In addition, surface root mean square (RMS) roughness of the films irradiated with intense electron beam affected strongly. The films irradiated by electron beam with 900 eV have the lowest roughness of 1.2 nm in this study.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.3
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• pp.83-88
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• 2015

Coating materials used in the electron beam (EB) deposition method, which is being studied as one of the fabrication methods of thermal barrier coating, are exposed to high power electron beam at focused area during the EB deposition. Therefore the coating source for EB process is needed to form as ingot with appropriate density and microstructure to sustain their shape and stable melts status during EB deposition. In this study, we tried to find the optimum powder condition for fabrication of ingot of 8 wt% yttria stabilized zirconia which can be used for EB irradiation. It seems that the ingot, which is fabricated through bi-modal type initial powder mixture which consists of tens of micro and nano size particles, was shown better performance than the ingot which is fabricated using monolithic nanoscale powder when exposed to high power EB.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.441-441
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• 2011

$TiO_2$ nanoparticles were grown on carbon fiber by atomic later deposition (ALD) with TTIP $(Ti(OCH(CH_3)_2)_4$ and $H_2O$ precusors. After sampe surfaces were treated by electron beam (1 MeV, 5 KGy), an improvement in the photocatalytic reacitivity of $TiO_2$ nanoparticles on carbon fiber was observed. An increase in the population of hydroxyl group on $TiO_2$ particles and the oxidation of carbon fiber were found upon e-beam exposure, whereas there was no noticeable changes of their morphology. It implies that those changes in O and C 1s state of $TiO_2$ particles/carbon fiber induced by e-beam treatment could be related to the enhancement of the photocatalytic activity. In contrast, when carbon fiber fully covered with $TiO_2$ thick films was treated with high-energy electron beam under same conditions, the improvement of photocatalytic activity as well as any changes in XPS spectra (Ti 2p, O 1s and C 1s) could not be found.