Al₂O₃ Passivation Effect in HfO₂·Al₂O₃ Laminate Structures Grown on InP Substrates

Kang, Hang-Kyu,Kang, Yu-Seon,Kim, Dae-Kyoung,Baik, Min,Song, Jin-Dong,An, Youngseo,Kim, Hyoungsub,Cho, Mann-Ho American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.20

<P>The passivation effect of an Al2O3 layer on the electrical properties was investigated in HfO2-Al2O3 laminate structures grown on indium phosphide (InP) substrate by atomic-layer deposition. The chemical state obtained using high-resolution X-ray photoelectron spectroscopy showed that interfacial reactions were dependent on the presence of the Al2O3 passivation layer and its sequence in the HfO2-Al2O3 laminate structures. Because of the interfacial reaction, the Al2O3/HfO2/Al2O3 structure showed the best electrical characteristics. The top Al2O3 layer suppressed the inter diffusion of oxidizing species into the HfO2 films, whereas the bottom Al2O3 layer blocked the outdiffusion of In and P atoms. As a result, the formation of In-O bonds was more effectively suppressed in the Al2O3/HfO2/Al2O3/InP structure than that in the HfO2-on-InP system. Moreover, conductance data revealed that the Al2O3 layer on InP reduces the midgap traps to 2.6 X 10(12) eV(-1) cm(-2) (compared to that of HfO2/InP, that is, 5.4 X 10(12) eV(-1) cm(-2)). The suppression of gap states caused by the outdiffusion of In atoms significantly controls the degradation of capacitors caused by leakage current through the stacked oxide layers.</P>

시멘트 구성성분을 이용한 시멘트/Fe(Ⅱ)의 TCE 환원성 탈염소화 반응의 유효반응 성분 규명

김홍석,정유연,황인성 한국지하수토양환경학회 2008 지하수토양환경 Vol.13 No.1

Experimental studies were conducted to identify the active agents for reductive dechlorination of TCE in cement/Fe(II) systems focusing on cement components such as CaO, Fe2O3, and Al2O3. A hematite that was used to simulate an Fe2O3 component in cement was found to have degradation efficiencies (k = 0.641 day-1) equivalent to that of cement/Fe(II) systems in the presence of CaO/Fe(II), only when it contained an aluminum impurity(Al2O3). When the effect of Al2O3 content of hematite/CaO/Al2O3/Fe(II) system was tested, the mole ratio of Al2O3 to CaO affected the rate of TCE degradation with an optimum ratio around 1 : 10 that resulted in a rate constant of 0.895 day-1. In the SEM images of hematite/CaO/Al2O3/Fe(II) systems, acicular crystals were also found that were also observed in cement/Fe(II) systems. Thus it was suspected that these crystals were reactive reductants and that they might be goethite or ettringite that are known to have acicular structures. An EDS element map analysis revealed that these crystals were not goethite crystals. A subsequent experiment that tested reactivities of compounds formed during the ettringite synthesis showed that ettringite and minerals associated with ettringite formation are not reactive reductants. These observations conclude that a mineral containing CaO and Al2O3 with a acicular structure could be a major reactive reductant of cement/Fe(II) systems. 본 연구는 시멘트 구성성분 중 CaO, Fe2O3, Al2O3를 중심으로 하여 시멘트/Fe(II) 시스템에서 TCE의 환원성 탈염소화에 관여하는 유효반응성분을 규명하기 위하여 수행되었다. Al2O3를 함유하는 것으로 밝혀진 hematite(Fe2O3)를 포함하는 hematite/CaO/Fe(II) 시스템에서 시멘트/Fe(II) 시스템과 유사한 TCE 분해능이 나타나는 것을 확인할 수 있었다. Hematite/CaO/Al2O3/Fe(II) 시스템에서 Al2O3의 첨가량의 영향을 알아보는 실험을 수행한 결과 Al2O3 : CaO의 비율이 1:10을 유지한 시스템에서 최고의 분해능(k = 0.895 day-1)을 보이는 것으로 보아 1 : 10이 최적의 반응비율인 것을 알 수 있었다. SEM 분석 결과 시멘트/Fe(II) 시스템에서 나타났던 막대결정을 hematite/CaO/Al2O3/Fe(II) 시스템에서도 관찰할 수 있었다. 이러한 막대결정을 TCE 분해의 유효성분으로 추정하고 막대나 침상 결정으로 알려진 goethite와 ettringite를 유효성분 후보군으로 판단하였다. EDS element map을 살펴본 결과, 막대 결정은 Ca를 주성분으로 하고 있었기 때문에 Fe 성분을 다량 함유하고 있는 goethite를 배제하였다. 추가적으로 시멘트 수화반응 중 ettringite가 생성되는 과정을 재연한 실험 결과, ettringite가 생성되는 반응 중 혹은 생성 후에도 TCE 분해능이 발현되지 않았다. 이러한 결과를 바탕으로 하여 시멘트/Fe(II) 시스템의 유효반응성분은 CaO와 Al2O3를 주성분으로 하는 막대모양의 결정일 것으로 판단된다.

Highly-impermeable Al₂O₃/HfO₂ moisture barrier films grown by low-temperature plasma-enhanced atomic layer deposition

Kim, Lae Ho,Jang, Jin Hyuk,Jeong, Yong Jin,Kim, Kyunghun,Baek, Yonghwa,Kwon, Hyeok-jin,An, Tae Kyu,Nam, Sooji,Kim, Se Hyun,Jang, Jaeyoung,Park, Chan Eon Elsevier 2017 Organic Electronics Vol.50 No.-

<P><B>Abstract</B></P> <P>Polymer substrates are essential components of flexible electronic applications such as OTFTs, OPVs, and OLEDs. However, high water vapor permeability of polymer films can significantly reduce the lifetime of flexible electronic devices. In this study, we examined the water vapor permeation barrier properties of Al<SUB>2</SUB>O<SUB>3</SUB>/HfO<SUB>2</SUB> mixed oxide films on polymer substrates. Al<SUB>2</SUB>O<SUB>3</SUB>/HfO<SUB>2</SUB> films deposited by plasma-enhanced atomic layer deposition were transparent, chemically stable in water and densely amorphous. At 60 °C and 90% relative humidity (RH) accelerated condition, 50-nm-thick Al<SUB>2</SUB>O<SUB>3</SUB>/HfO<SUB>2</SUB> had water vapor transmission rate (WVTR) = 1.44 × 10<SUP>−4</SUP> g m<SUP>−2</SUP> d<SUP>−1</SUP>, whereas single layers of Al<SUB>2</SUB>O<SUB>3</SUB> had WVTR = 3.26 × 10<SUP>−4</SUP> g m<SUP>−2</SUP> d<SUP>−1</SUP> and of HfO<SUB>2</SUB> had WVTR = 6.75 × 10<SUP>−2</SUP> g m<SUP>−2</SUP> d<SUP>−1</SUP>. At 25 °C and 40% RH, 50-nm-thick Al<SUB>2</SUB>O<SUB>3</SUB>/HfO<SUB>2</SUB> film had WVTR = 2.63 × 10<SUP>−6</SUP> g m<SUP>−2</SUP> d<SUP>−1</SUP>, which is comparable to WVTR of conventional glass encapsulation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Al<SUB>2</SUB>O<SUB>3</SUB>, HfO<SUB>2</SUB>, and Al<SUB>2</SUB>O<SUB>3</SUB>/HfO<SUB>2</SUB> mixed oxide films were deposited by plasma-enhanced atomic layer deposition (PEALD). </LI> <LI> Al<SUB>2</SUB>O<SUB>3</SUB>/HfO<SUB>2</SUB> mixed oxide films were prepared by alternating deposition of Al<SUB>2</SUB>O<SUB>3</SUB> and HfO<SUB>2</SUB> (one layer of each per cycle). </LI> <LI> Al<SUB>2</SUB>O<SUB>3</SUB>/HfO<SUB>2</SUB> mixed oxide films had densely-packed amorphous structure due to Al<SUB>2</SUB>O<SUB>3</SUB> and high chemical stability due to HfO<SUB>2</SUB>. </LI> <LI> All Al<SUB>2</SUB>O<SUB>3</SUB>/HfO<SUB>2</SUB> mixed oxide films were less permeable to moisture than were single Al<SUB>2</SUB>O<SUB>3</SUB> or HfO<SUB>2</SUB> films. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

플라즈마 스프레이 방법으로 코팅 된 $Al_2O_3$막의 구조적 특성

김좌연,유재근,설용태,Kim, Jwa-Yeon,Yu, Jae-Keun,Sul, Yong-Tae 한국결정성장학회 2006 韓國結晶成長學會誌 Vol.16 No.3

반도체 드라이 에처 시스템의 웨이퍼 정전기 척에 적용하기 위해 플라즈마 스프레이 방법으로 Al-60 계열 기판에 코팅한 $Al_2O_3$ 코팅 막의 특성을 조사하였다. 시편 뒷면에 냉각봉이 장착되었을 때와 없을 때, 용사거리와 분말공급량을 변형하면서 $Al_2O_3$ 막 코팅을 하여 시편을 제작 하였다. 시편 뒷면에 냉각봉이 없을 때는 크랙과 기공이 많이 발생하였다. 시편 뒷면에 냉각봉을 장착하고 분말공급량을 15g/min로 한 경우에 용사거리 60, 70, 80mm에 따른 $Al_2O_3$ 코팅에서는 크랙과 기공은 거의 찾아볼 수 없었다. 용사거리 변화에 따른 $Al_2O_3$ 막 코팅의 표면형태 변화는 없었다. 같은 공정조건에서 분말 공급량을 20g/min로 한 경우에도 크랙은 볼 수 없었으나 약간의 기공이 생겼고, 분말공급량을15g/min로 하였을 때 보다 작은 입자들이 많이 증착되었다. 시편 뒷면에 냉각봉이 없을 때가 시편 뒷면에 냉각봉이 장착된 경우에 비하여 증착 속도가 빨랐다. We have investigated plasma spray coated $Al_2O_3$ layers on Al-60 series substrates for development of wafer electrostatic chuck in semiconductor dry etching system. Samples were prepared without/with cooling bar on backside of samples, at various distances, and with different powder feed rates. There were many cracks and pores in the $Al_2O_3$ layers coated on Al-60 series substrates without cooling bar on the backside of samples. But the cracks and pores were almost disappeared in the $Al_2O_3$ layers on Al-60 series substrates coated with cooling bar on the back side of samples, 15 g/min. powder feed rate and various 60, 70, 80 mm working distances. Then the surface morphology was not changed with various working distances of 60, 70, 80 mm. When the powder feed rate was changed from 15 g/min to 20 g/min, the crack did not appear, but few pores appeared. Also the $Al_2O_3$ layer was coated with many small splats compared with $Al_2O_3$ layer coated with 15 g/min powder feed rate. The deposited rate of $Al_2O_3$ layer was higher when the process was done without cooling bar on the back side of sample than that with cooling bar on the back side of sample.

에어로졸 증착 공정을 통해 제작한 Al2O3 코팅층의 Al2O3 입자 크기에 따른 성막 메커니즘 연구

김익수,조명연,구상모,이동원,오종민 한국전기전자재료학회 2020 전기전자재료학회논문지 Vol.33 No.3

Al2O3 powders with particle sizes of 0.35 μm, 0.5 μm, 1.5 μm, and 2.5 μm are deposited onto glass and Cu substrates using the aerosol deposition (AD) process. The deposition characteristics of Al2O3 films using those four types of Al2O3 powders are investigated to determine the influence of the particle size on the films. To observe detailed micro-structures of the films, the cross-section and surface morphology are observed. Then, the crystalline size and internal strain are calculated from X-ray diffraction peaks in order to confirm the hammering effect as well as the micro-strain during the AD deposition. From the above results, deposition mechanisms related to the particle size are studied. The results of this study indicate the optimal particle size and formation mechanisms for dense Al2O3 film with a smooth surface roughness as well as for a porous Al2O3 film with a rough surface roughness. 0.35 μm, 0.5 μm, 1.5 μm 및 2.5 μm의 입자 크기가 다른 Al2O3 분말이 에어로졸 증착 공정을 통해 유리 기판과 구리 기판에 증착되었다. 입자 크기가 코팅층 성막에 미치는 영향을 알아보기 위해 네 종류의 Al2O3 분말을 사용하여 코팅된 Al2O3 필름의 성막 특성을 조사하였다. Al2O3 필름의 미세구조를 자세히 분석하기 위해, 단면과 표면 형상을 관찰하였다. 또한, 증착이 일어나는 동안 미세 변형과 망치 효과를 확인하기 위해 X-ray 회절 피크로부터 결정 크기 및 내부 변형을 계산하였다. 상기의 분석 결과로부터, 입자 형상과 관련지어 증착 메커니즘을 연구하였다. 본 연구에서는 거친 표면 거칠기를 갖는 다공성 Al2O3 필름뿐만 아니라 부드러운 표면 거칠기를 갖는 치밀한 Al2O3 필름 제작을 위한 최적의 입자 크기를 각각 제안하고자 한다.

Effects of heat treatment on the dielectric properties of aerosol-deposited Al2O3-polyimide composite thick films for room-temperature fabrication

Hyung-Jun KIM,Song-Min NAM 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.6

Al2O3-polyimide composite thick films for integrated substrates were successfully fabricated at room temperature by an aerosol deposition method (ADM). When using as-received a-Al2O3 as a starting powder, the Al2O3-polyimide composite thick films exhibited a high dielectric loss and high frequency dependence. The relative permittivity and tan δ of the Al2O3-polyimide composite thick films using as-received Al2O3 powder were 6.7 and 0.026 at 1MHz, respectively. However, their dielectric loss was remarkably decreased from 0.026 to 0.007 at 1MHz after post-annealing at 100℃ although their relative permittivity did not change. It was determined that the decreases of dielectric loss mainly depended on the state of the Al2O3. Based on these results, the heat treatment of the Al2O3 starting powder was carried out in order to fabricate Al2O3-polyimide composite films with a low dielectric loss at room temperature. As a result, their tan δ was also decreased from 0.026 to 0.007 without a long post-annealing. It was confirmed that the preparation of the ceramic Al2O3 starting powder was important for the roomtemperature fabrication of the aerosol deposited Al2O3-polyimide composite thick films with a low dielectric loss. Al2O3-polyimide composite thick films for integrated substrates were successfully fabricated at room temperature by an aerosol deposition method (ADM). When using as-received a-Al2O3 as a starting powder, the Al2O3-polyimide composite thick films exhibited a high dielectric loss and high frequency dependence. The relative permittivity and tan δ of the Al2O3-polyimide composite thick films using as-received Al2O3 powder were 6.7 and 0.026 at 1MHz, respectively. However, their dielectric loss was remarkably decreased from 0.026 to 0.007 at 1MHz after post-annealing at 100℃ although their relative permittivity did not change. It was determined that the decreases of dielectric loss mainly depended on the state of the Al2O3. Based on these results, the heat treatment of the Al2O3 starting powder was carried out in order to fabricate Al2O3-polyimide composite films with a low dielectric loss at room temperature. As a result, their tan δ was also decreased from 0.026 to 0.007 without a long post-annealing. It was confirmed that the preparation of the ceramic Al2O3 starting powder was important for the roomtemperature fabrication of the aerosol deposited Al2O3-polyimide composite thick films with a low dielectric loss.

N-type 결정질 실리콘 태양전지 응용을 위한 Al₂O₃ 박막의 패시베이션 특성 연구

정명일,최철종,Jeong, Myung-Il,Choi, Chel-Jong 한국결정성장학회 2014 한국결정성장학회지 Vol.24 No.3

Atomic layer deposition(ALD)을 이용하여 $Al_2O_3$ 박막을 형성하고 이에 대한 패시베이션 특성에 대한 연구를 수행하였다. ALD로 증착된 $Al_2O_3$ 박막은 $400^{\circ}C$ 5분간 후속 열처리 공정 후에도 $Al_2O_3$ - 실리콘 계면 반응 없이 비정질 상태를 유지할 만큼 구조적으로 안정한 특성을 나타내었다. 후속 열처리 후 $Al_2O_3$ 박막의 패시베이션 특성이 향상되었으며, 이는 field effective 패시베이션과 화학적 패시베이션 효과가 동시에 상승에 기인하는 것으로 판단된다. $Al_2O_3$ 박막의 음고정 전하를 정량적으로 평가하기 위해서 후속 열처리 공정을 거친 $Al_2O_3$ 박막을 이용하여 metal-oxide-semiconductor(MOS) 소자를 제작하고 capacitance-voltage(C-V) 분석을 수행하였다. C-V 결과로부터 추출된 flatband voltage($V_{FB}$)와 equivalent oxide thickness(EOT)의 관계식을 통하여 $Al_2O_3$ 박막의 고정음전하는 $2.5{\times}10^{12}cm^{-2}$로 계산되었으며, 이는 본 연구에서 제시된 $Al_2O_3$ 박막 공정이 N-type 실리콘 태양전지의 패시베이션 공정에 응용 가능하다는 것을 의미한다. The passivation property of $Al_2O_3$ thin film formed using atomic layer deposition (ALD) for the application of crystalline Si solar cells was investigated using microwave photoconductance decay (${\mu}$-PCD). After post-annealing at $400^{\circ}C$ for 5 min, $Al_2O_3$ thin film exhibited the structural stability having amorphous nature without the interfacial reaction between $Al_2O_3$ and Si. The post-annealing at $400^{\circ}C$ for 5 min led to an increase in the relative effective lifetime of $Al_2O_3$ thin film. This could be associated with the field effective passivation combined with surface passivation of textured Si. The capacitance-voltage (C-V) characteristics of the metal-oxide-semiconductor (MOS) with $Al_2O_3$ thin film post-annealed at $400^{\circ}C$ for 5 min was carried out to evaluate the negative fixed charge of $Al_2O_3$ thin film. From the relationship between flatband voltage ($V_{FB}$) and equivalent oxide thickness (EOT), which were extracted from C-V characteristics, the negative fixed charge of $Al_2O_3$ thin film was calculated to be $2.5{\times}10^{12}cm^{-2}$, of which value was applicable to the passivation layer of n-type crystalline Si solar cells.

Mn-Cu/Al₂O₃ 촉매 상에서 NO, CO 및 CH₄ 동시 산화

정지은 ( Ji Eun Jeong ),이창용 ( Chang-yong Lee ) 한국공업화학회 2024 공업화학 Vol.35 No.1

NO, CO 및 CH₄의 동시 산화를 위한 4 종의 Mn-M/Al₂O₃ (M = Cu, Fe, Co, Ce) 촉매를 제조하여 산화 활성을 비교하고, 동시 산화활성이 가장 높은 Mn-Cu/Al₂O₃ 촉매에 대해 XRD, Raman, XPS, O₂-TPD 분석을 수행하였다. XRD 분석 결과, Mn-Cu/Al₂O₃ 촉매에서는 담지된 Mn과 Cu는 복합산화물로 존재하였다. Raman 및 XPS 분석을 통해 Mn-Cu/Al₂O₃ 촉매는 Mn-O-Cu 결합의 형성 과정에서 Mn 이온과 Cu 이온 간의 전자 수수가 일어남을 알 수 있었다. XPS O 1s 및 O₂-TPD 분석을 통해 Mn-Cu/Al₂O₃ 촉매는 Mn/Al₂O₃ 촉매에 비해 이동성이 우수한 흡착산소 종이 증가했음을 알 수 있었다. Mn-Cu/Al₂O₃ 촉매의 높은 동시 산화 활성은 이러한 결과에 기인한다고 판단된다. Mn-Cu/Al₂O₃ 촉매 상에서 NO는 CO와 CH₄ 산화를 촉진하지만, NO 산화는 억제되었다. 이는 NO로부터 산화된 NO₂가 CO 및 CH₄의 산화제로 사용되었기 때문이라고 추측된다. CO와 CH₄의 산화 반응은 경쟁하지만 촉매 활성 온도가 다르기 때문에 그 효과가 두드러지지 않았다. Mn-M/Al₂O₃ (M = Cu, Fe, Co, and Ce) catalysts were prepared for simultaneous oxidation of NO, CO, and CH₄, and their oxidation activities were compared. The Mn-Cu/ Al₂O₃ catalyst with the best simultaneous oxidation activity was characterized by XRD, Raman, XPS, and O₂-TPD analysis. The result of XRD indicated that Mn and Cu existed as complex oxides in the Mn-Cu/Al₂O₃ catalyst. Raman and XPS results showed that electron transfer between Mn ions and Cu ions occurred during the formation of the Mn-O-Cu bond in the Mn-Cu/Al₂O₃ catalyst. The XPS O 1s and O₂-TPD analyses showed that the Mn-Cu/Al₂O₃ catalyst has more adsorbed oxygen species with high mobility than the Mn/Al₂O₃ catalyst. The high simultaneous oxidation activity of the Mn-Cu/Al₂O₃ catalyst is attributed to these results. Gas-phase NO promotes the oxidation reactions of CO and CH₄ in the Mn-Cu/Al₂O₃ catalyst while suppressing the NO oxidation reaction. These results were presumed to be because the oxidized NO was used as an oxidizing agent for CO and CH₄. On the other hand, the oxidation reactions of CO and CH₄ competed on the Mn-Cu/Al₂O₃ catalyst, but the effect was not noticeable because the catalyst activation temperature was different.

NO_x Reduction Characteristics for Different Composition Ratios of Pt/Al₂O₃, Rh/Al₂O₃ Catalyst Mixtures Using Model Gas as Reformates

Chung, Jinhwa,Lim, Suchol,Ha, Jongju,Song, Soonho,Chun, Kwangmin WILEY-VCH Verlag 2010 Chinese journal of chemistry Vol.28 No.7

<P>This study investigated the selective catalytic reduction (SCR) of nitrogen oxides (NO<SUB>x</SUB>) with hydrocarbon in the presence of excess oxygen using various composition ratios of Pt/Al<SUB>2</SUB>O<SUB>3</SUB>, Rh/Al<SUB>2</SUB>O<SUB>3</SUB> catalyst mixtures. The composition ratios were 1:1, 1:2, 2:1, 1:3 and 3:1 of 1 wt% Pt/Al<SUB>2</SUB>O<SUB>3</SUB> and Rh/Al<SUB>2</SUB>O<SUB>3</SUB>, which are known to exhibit efficient NO<SUB>x</SUB> reduction at low and high temperatures among the noble metal catalysts. Experiments conducted on a single reductant revealed that more efficient NO<SUB>x</SUB> conversion could be obtained when Pt/Al<SUB>2</SUB>O<SUB>3</SUB> and Rh/Al<SUB>2</SUB>O<SUB>3</SUB> were mixed at a ratio of 3:1, rather than 1:1 or 1:3. In a single reductant condition, C<SUB>3</SUB>H<SUB>6</SUB> 800 ppm (2400 ppmC<SUB>1</SUB>) and 400 ppm (1200 ppmC<SUB>1</SUB>) exhibited 50% and 38% NO<SUB>x</SUB> conversion efficiency at 200°C, respectively. However, NO<SUB>x</SUB> conversion efficiency gradually decreased when temperatures were increased above 250°C. With regard to Pt/Al<SUB>2</SUB>O<SUB>3</SUB> and Rh/Al<SUB>2</SUB>O<SUB>3</SUB> ratio, higher ratios of Rh/Al<SUB>2</SUB>O<SUB>3</SUB> activated this Pt+Rh/Al<SUB>2</SUB>O<SUB>3 </SUB>catalyst in the high temperature range.</P> <B>Graphic Abstract</B> <P>This study investigated the selective catalytic reduction (SCR) of nitrogen oxides (NO<SUB>x</SUB>) with hydrocarbon in the presence of excess oxygen using various composition ratios of Pt/Al<SUB>2</SUB>O<SUB>3</SUB>, Rh/Al<SUB>2</SUB>O<SUB>3</SUB> catalyst mixtures. The composition ratios were 1:1, 1:2, 2:1, 1:3, and 3:1 of 1 wt% Pt/Al<SUB>2</SUB>O<SUB>3</SUB> and Rh/Al<SUB>2</SUB>O<SUB>3</SUB>, which are known to exhibit efficient NO<SUB>x</SUB> reduction at low and high temperatures among the noble metal catalysts. <img src='wiley_img_2010/1001604X-2010-28-7-CJOC201090190-content.gif' alt='wiley_img_2010/1001604X-2010-28-7-CJOC201090190-content'> </P>

연소합성법에 의한 $MoSi_2-Al_2O_3$ 복합재료의 특성에 미치는 $Mo/MoO_3$ 몰비의 영향

장윤식,이윤복,김용백,김인술,박흥채,오기동 한국세라믹학회 1996 한국세라믹학회지 Vol.33 No.11

MoSi2-Al2O3 composites were prepared by thermal explosion mode of self-propagating high temperature syn-thesis (SHS) using element powders of MoO3 Mo Si and Al. The combustion products of MoSi2 which have 10, 20, 30 and 40 wt% Al2O3 showed the molten state in the range of Mo to MoO3 6:1-9.5:1, 2:1-8:1, 1:1-5:1, and 1:1-3:1 (molar ratio) respectively. The combustion products which made least seperation the molten phase from the slag phase were in Mo/MoO3=9, 5:1, 8:1, 5:1 and 3:1 (molar ratio) respectively. Particles size of MoSi2 and Al2O3 in the combustion product were decreased as the molar ratio of Mo to MoO3 increase. By XRD analysis only MoSi2 and $\alpha$-Al2O3 peaks were identified in the combusion products, In case of MoSi2 containing 20wt% Al2O3 5.1wt% Al existed into MoSi2 grains and 30.7wt% Si and 7.7wt% Mo existed into Al2O3 grains. The relative density of MoSi2 containing 10, 20, 30 and 40 wt% Al2O3 were 82.7, 85.2, and 81.9% respectively. The fracture strength of MoSi2-Al2O3 composites increased with increasing Al2O3 and that of MoSi2-20wt% Al2O3 composite was 195 MPa.