• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.376-380
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• 2003

The microstructure and the mechanical properties of RS-SiC and RS-$SiC_f/SiC$ materials have been investigated in conjunction with the content of residual silicon and porosity. The mechanical properties of RS-SiC materials suffered from the thermal exposure were also examined. RS-SiC based materials bave been fabricated using the complex matrix slurry with different composition ratios of SiC and C panicles. The characterization of RS-SiC based materials was investigated by means of SEM, EDS ~d three point bending test. Based on the mechanical property-microstructure correlation, the high temperature applicability of RS-SiC based materials was discussed.

• 대한기계학회논문집A
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• 제29권3호
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• pp.425-431
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• 2005

The efficiency of complex slurry preparation route for developing the high performance SiC matrix of $RS-SiC_{f}/SiC$ composites has been investigated. The green bodies for RS-SiC materials prior to the infiltration of molten silicon were prepared with various C/SiC complex slurries, which associated with both the sizes of starting SiC particles and the blending conditions of starting SiC and C particles. The characterization of Rs-SiC materials was examined by means of SEM, EDS and three point bending test. Based on the mechanical property-microstructure correlation, the process optimization is also discussed. The flexural strength of Rs-SiC materials greatly depended on the content of residual Si. The decrease of starting SiC particle size in the C/SiC complex slurry was effective for improving the flexural strength of RS-SiC materials.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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• pp.102-105
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• 2005

The mechanical properties of $SiC_f/SiC$ composites reinforced with continuous SiC fiber have been investigated in conjunction with the detailed analysis of their microstructures. Especially, the effect of test temperature on the characterization of $SiC_f/SiC$ composites was examined. In this composite system, a braiding Hi-Nicalon SiC fibric was selected as a reinforcement. $SiC_f/SiC$ composites have been fabricated by the reaction sintering process, using the complex matrix slurry with a constant composition ratio of SiC and C particles. The characterization of $RS-SiC_f/SiC$ composites was investigated by means of SEM, EDS and three point bending test. Based on the mechanical property-microstructure correlation, the high temperature applicability of $RS-SiC_f/SiC$ composites was discussed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.166-171
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• 2007

The characterization of monolithic SiC and SiCf/SiC composite materials fabricated by NITE and RS processes was investigated in conjunction with the detailed analysis of their microstructure and density. The NITE-SiC based materials were fabricated, using a SiC powder with average size of 30 nm. RS- SiCf/SiC composites were fabricated with a complex slurry of C and SiC powder. In the RS process, the average size of starting SiC particle and the blending ratio of C/SiC powder were $0.4\;{\mu}m$ and 0.4, respectively. The reinforcing materials for /SiC composites were BN-SiC coated Hi-Nicalon SiC fiber, unidirectional or plain woven Tyranno SA SiC fiber. The characterization of all materials was examined by the means of SEM, EDS and three point bending test. The density of NITE-SiCf/SiC composite increased with increasing the pressure holding time. RS-SiCf/SiC composites represented a great decrease of flexural strength at the temperature of $1000\;^{\circ}C.$

• 한국재료학회지
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• 제10권12호
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• pp.812-818
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• 2000

본 연구에서는 Ge PAM이 선폭 미세화에 따른 C54 실리사이드화 및 실제 CMOS 트랜지스터 접합부에서의 각종 전기적 특성에 미치는 영향을, As PAM과의 비교를 통하여 관찰하였다. 평판 상에서 각 PAM 및 기판의 도핑 상태에 따른 Rs의 변화량을 측정하였으며, 각 PAM 방식은 기존의 살리사이드 TiSi$_2$에 비해 개선된 C54 형성 효과를 보였다. 특히, Ge PAM은 n+ 기판에서 As PAM보다 효과적인 실리사이드화를 보였고, 이 경우 XRB 상에서도 가장 강한 (040) C54 배향성을 나타내었다. ~0.25$\mu\textrm{m}$ 선폭 및 n+ 접합층에서 기존 방식에 비해 As과 Ge PAM은 각각 ~85,66%의 개선된 바저항을 보였으며, P+ 접합층에서는 As과 Ge PAM 모두 62~63% 정도의 유사한 Rs 개선 효과를 보였다. 콘택 저항에서도 각 콘택 크기 별로 바저항(bar resistance) 개선과 같은 경향의 PAM 효과를 관찰하였으며, 모든 경우 10 $\Omega$/ct. 이하로 양호한 결과를 보였다. 누설 전류는 area 형 패턴에서는 모든 공정 조건에서 <10E-14A/$\mu\textrm{m}^{2}$ 이하로, edge 형에서는 특히 P+ 접합부에서 As 또는 Ge PAM 적용 시 <10E-13 A/$\mu\textrm{m}^{2}$ 이하로 다소 누설 전류를 안정화시키는 결과를 보였다. 이러한 결과는 XTEM에 의해 관찰된 바 Ge PAM 적용 시 기존의 경우에 (PAM 적용 안한 경우) 비해 유사한 평활도의 TiSi$_2$박막 형상과 일치하였으며, 또한 본 실험의 Ge PAM 이온주입 조건이 접합층에 손상을 주지 않는 범위에서 적정화되었음을 제시하였다

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2003년도 하계학술연구발표회 및 한.일 공동심포지엄
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• pp.88-89
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• 2003

During the past decade, giant magnetotransport phenomena such as giant magetoresistance (GMR) in thin films and in manganese perovskites, and, giant magnetoimpedance (GMI) in soft magnetic amorphous ribbons, have brought much interest in the basic physical understanding and their applications as magnetic recording heads and in magnetic sensors technology. Among the parameters required for the quality of a magnetic sensor, temperature dependences of GMR and GMI profiles are playing an important role. In the present work, we have studied temperature dependences of the longitudinal permeability and giant magnetoimpedance effect in $Co_{70}$F $e_{5}$S $i_{15}$ N $b_{2.2}$C $u_{0.8}$ $B_{7}$ amorphous ribbons expecting as a promising candidate in the domain of magnetic sensors.rs.rs.rs.s.

• 한국재료학회지
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• 제7권3호
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• pp.213-217
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• 1997

200MHz 응향광변조기 (AOM: Acousto-Optic Modulator)는 제 2고조파(SHG: Second Harmonic Generation)녹색 레이저와 함께 DVDR(Digital Video Disk Recorder)에 적용되어 고밀도 광기록용으로 사용되었다. 이러한 고밀도 광기록 장치로써 사용되기 위해서는 고출력 레이저의 사용이 필수적이며, 레이저 빔이 통과하는 각 광학 소자들의 코팅막은 고출력 레이저 빔에 대해 높은 레이저 damage threshold를 가져야 한다. AOM의 음향공학재료로 사용되는 $TeO_{2}$단결정에 코팅막의 종류 및 증착조건을 변화시키며 E-beam 증착법으로 A/R코팅 시편을 준비하였다. 0.55W의 입력 power를 갖는Ar레이저를 사용하여 코팅의 광손상 정도를 확인하였다. $AI_{2}O_{3}$막에 비해 $ZrO_{2}$와 $SiO_{2}$막을 사용한 경우 레이저 damage threshold는 크게 향상되었다. 또한 AOM모듈을 제작 후 구동회로와 연결하여 약 20mW의 SHG power를 입력시키며 출력 power long term안정성을 측정하였다.

• Bulletin of the Korean Chemical Society
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• 제28권2호
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• pp.251-256
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• 2007

The crystal structure of fully dehydrated partially Cs+-exchanged zeolite X, [Cs52Na40Si100Al92O384], a = 24.9765(10) A, has been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd3 at 21 °C. The crystal was prepared by flow method for 5 days using exchange solution in which mole ratio of CsOH and CsNO3 was 1 : 1 with total concentration of 0.05 M. The crystal was then dehydrated at 400 °C and 2 × 10-6 Torr for 2 days. The structure was refined to the final error indices, R1 = 0.051 and wR2 (based on F2) = 0.094 with 247 reflections for which Fo > 4σ (Fo). In this structure, about fifty-two Cs+ ions per unit cell are located at six different crystallographic sites with special selectivity; about one Cs+ ion is located at site I, at the centers of double oxygen-rings (D6Rs), two Cs+ ions are located at site I', and six Cs+ ions are found at site II'. This is contrary to common view that Cs+ ions cannot pass sodalite cavities nor D6Rs because six-ring entrances are too small. Ring-opening by the formation of ?OH groups and ring-flexing make Cs+ ions at sites I, I', and II' enter six-oxygen rings. The defects of zeolite frameworks also give enough mobility to Cs+ ions to enter sodalite cavities and D6Rs. Another six Cs+ ions are found at site II, thirty-six are located at site III, and one is located at site III' in the supercage, respectively. Forty Na+ ions per unit cell are located at two different crystallographic sites; about fourteen are located at site I, the centers of D6Rs and twenty-six are also located at site II in the supercage. Cs+ ions and Na+ ions at site II are recessed ca. 0.34(1) A and 1.91(1) A into the supercage, respectively. In this work, the highest exchange level of Cs+ ions per unit cell was achieved in zeolite X by conventional aqueous solution methods and it was also shown that Cs+ ion could pass through the sixoxygen rings.