• 한국재료학회:학술대회논문집
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• 한국재료학회 1996년도 재료학회 춘계학술발표회
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• pp.54-54
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• 1996

• 대한화학회지
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• 제12권2호
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• pp.65-80
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• 1968

9種의 選擇된 탈리움硼硅酸유리와 21種의 同類組成을 變化시킨 유리에 對하여 物理化學的 性質을 檢討하였다. 이들 組成에 依한 性質의 變化曲線은 여러 點에서 酸化리티움, 소다 및 酸化鉛들을 包含하는 다른 硼硅酸유리와 類似하였다. 탈리움 硼硅酸유리의 組成에 따른 成質의 變化曲線에 極少點이 나타났는데, 이는 $Na_2O-B_2O_3-SiO_2$유리에서 關察된 바와 같이 硼素結合의 變化에 基因되는 것 같다. 탈리움 이온이 硼硅酸유리에 미치는 主 影響을 綜合해 보면 다음과 같다. 1) 탈리움 이온을 添加함으로써 密度, 屈折率, 물에 對한 溶解度, 熱線膨脹係數, 誘電恒數 等이 增加되었다. 2) 탈리움 濃度을 增加시킴으로써 유리의 軟化點이 降下되었고, 紫外線 照射에 依하여 螢光이 생겼으며, 赤外線 $15{\mu}$까지의 吸收端이 不明確해 졌다. $Tl_2O-B_2O_3-SiO_2$ 系에서 廣範한 液體不混合性이 電子顯微鏡에 依해 밝혀졌다. 不混合性은 $B_2O_3-SiO_2$ 二成分系에 對하여 約 $Tl_2O$ 55wt.%의 組成範圍內에서 나타났다. 不混合性유리는 多硅酸과 多硅素相으로 分離 構成되어 있음이 酸處理에 依하여 밝혀졌다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권7호
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• pp.394-399
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• 2000

The mechanical and electrical properties of pressed and annealed $\beta-SiC-TiB_2$ electroconductive ceramic composites were investigated as a function of the liquid forming additives of $Al_2O_3+Y_2O_3$. Phase analysis of composites by XRD revealed $\alpha$-SiC(6H), TiB2, and (Al5Y3O12). Reaction between Al2O3 and $Y_2O_3$ formed YAG but the relative density decreased with increasing $Al_2O_3+Y_2O_3$ contents. The Flexural strength showed the value of 458.9 MPa for composites added with 4 wt% $Al_2O_3+Y_2O_3$ additives at room temperatures. Owing to crack deflection and crack bridging, the fracture toughness showed 6.2, 6.0 and 6.6 MPa.m1/2 for composites added with 4, 8 and 12 wt% Al2O3+Y2O3 additives respectively at room temperature. The resistance temperature coefficient showed the value of $3.6\times10^{-3},\; 2.9\times10^{-3}\; and\; 3.0\times10^{-3} /^{\circ}C$$^{\circ}C$ for composite added with 4, 8 and 12 wt% $Al_2O_3+Y_2O_3$additives respectively at room temperature. The electrical resistivity of the composites was all positive temperature coefficient resistance(PTCR) in the temperature range of $25^{\circ}C\; to\; 700^{\circ}$.

• 한국세라믹학회지
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• 제25권6호
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• pp.609-614
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• 1988

This study was carried out to investigate the effects of B4C or Y2O3 additives on the tendency of sintering, $\beta$-SiC synthesis and mineral phase changes by reaction bonding of SiC at 145$0^{\circ}C$. At the sintering temperature of 145$0^{\circ}C$, the additives such as B4C or Y2O3 did not improved porosity and bending strength. Added more than 1.5% of Y2O3, 0.5-0.3% of B4C, the formation of $\beta$-SiC was increased. At higher temperature above 145$0^{\circ}C$, it seems that the bodies added B4C, contained 3C form of SiC were denser than that of Y2O3 added. Because the transition of 3Clongrightarrow4Hlongrightarrow6H promoted sintering.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2001년도 추계 학술발표강연 및 논문개요집
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• pp.189-189
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• 2001

• 자원리싸이클링
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• 제20권3호
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• pp.55-61
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• 2011

금속급 실리콘(MG-Si)을 태양전지용 실리콘(SOG-Si)으로 정제하기 위한 경제적인 프로세스를 구축하기 위하여 1823 K에서 CaO-$SiO_2$ 계 슬래그에 의한 붕소의 제거에 대하여 조사하였다. 본 연구에서 CaO-$SiO_2$와 $CaCO_3-SiO_2$ 슬래그의 염기도(%CaO/$%SiO_2$) 증가에 따라 B의 제거율은 각각 63%와 73%까지 증가하였다. 그러나 Ar 가스에 의한 슬래그와 실리콘의 교반 시간의 영향은 나타나지 않았다. 그리고 CaO-$SiO_2$ 계 슬래그에 $Na_2CO_3$를 첨가하였으나 그 영향은 크지 않았다. $CaCO_3-SiO_2$ 슬래그(염기도=1.2)에 의해 3회 처리한 결과 B의 농도는 1.03 ppm까지 감소하였다.

• 한국재료학회지
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• 제14권4호
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• pp.246-250
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• 2004

We have investigated the effects of boron added to Cu film on the Cu-Ti reaction and microstructural evolution of Cu(B) alloy film during annealing of Cu(B)/Ti/$SiO_2$/Si structure. The result were compared with those of Cu(B)/$SiO_2$ structure to identify the effects of Ti glue layers on the Boron behavior and the result grain growth of Cu(B) alloy. The vacuum annealing of Cu(B)/Ti/$SiO_2$ multilayer structure allowed the diffusion of B to the Ti surface and forming $TiB_2$ compounds at the interface. The formed $TiB_2$ can act as a excellent diffusion barrier against Cu-Ti interdiffusion up to $800^{\circ}C$. Also, the resistivity was decreased to $2.3\mu$$\Omega$-cm after annealing at $800^{\circ}C$. In addition, the presence of Ti underlayer promoted the growth Cu(l11)-oriented grains and allowed for normal growth of Cu(B) film. This is in contrast with abnormal growth of randomly oriented Cu grains occurring in Cu(B)/$SiO_2$ upon annealing. The Cu(B)/Ti/$SiO_2$ structure can be implemented as an advanced metallization because it exhibits the low resistivity, high thermal stability and excellent diffusion barrier property.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1913-1915
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• 1999

The ${\beta}-SiC+ZrB_2$ ceramic composites were hot-press sintered and annealed by adding 1, 2, 3wt% $Al_2O_3+Y_2O_3$(6 : 4wt%) powder as a liquid forming additives at $1950^{\circ}C$ for 4h. In this microstructures, no reactions were observed between $\beta$-SiC and $ZrB_2$, and the relative density is over 90.79% of the theoretical density and the porosity decreased with increasing $Al_2O_3+Y_2O_3$ contents. Phase analysis of the composites by XRD revealed of $\alpha$-SiC(6H, 4H), $ZrB_2$, $Al_2O_3$ and $\beta$-SiC(15R). Flexural strength showed the highest of 315.46MPa for composites added with 3wt% $Al_2O_3+Y_2O_3$ additives at room temperature. Owing to crack deflection and crack bridging of fracture toughness mechanism, the fracture toughness showed the highest of $5.5328MPa{\cdot}m^{1/2}$ for composites added with 2wt% $Al_2O_3+Y_2O_3$ additives at room temperature.

• 한국세라믹학회지
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• 제23권2호
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• pp.13-20
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• 1986

Composite polycrystals including ${\gamma}$-$6Bi_2O_3$.$SiO_2$ crystal which have needlelike regular structure are useful for the high resolution optical devices. For the purpose of obtaining the composite polycrystals described above the melts of eutectic composition in the three eutectic systems including $6Bi_2O_3$.$SiO_2$ composition were unidirectionally solidified at a rate of 0.05 and 0.25 cm/h under a thermal gradient of 10$0^{\circ}C$/m. Composite polycrystals of relatively regular structure in which needlelike ${\gamma}$-$6Bi_2O_3$.$SiO_2$ crystals were arrayed in parallel with $2Bi_2O_3$.$B_2O_3$ crystal matrix were obtained when the eutectic melt of $6Bi_2O_3$.$SiO_2 -2Bi_2O_3$.$B_2O_3$ system was solidified at a rate of 0.25 cm/h. Partial structural irregularity however was found in the obtained composite polycrystals.

• 한국세라믹학회지
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• 제33권4호
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• pp.385-390
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• 1996

The electrical resistivity of the ceramic glaze coated on ceramic substrate plays an important role on the characteristics of the thick and thin film electrical circuits. In this study the effects of the various modifiers on the electrical resistivity were examined in SiO2-Al2O3-B2O3-RO-Na2O (RO=CaO , SrO, BaO, PbO) glass system. In alkali free glasses where divalent cations are responsible for electrical conduction the electrical conductivity of th glasses increased with the ionic size of divalent cations due to the decrease in the bond strength between oxyben and divalent cation. In Na2O containing glasses however where Na+ ion is responsible for electrical conduction the ionic conductivity decreased with the ionic size of divalent cations because the blocking effect of the cations on Na+ ion movement increased with larger divalent cations. Na+ ionic conduction also depended on the glass structure relaxation due to the corrdination number changes of B2O3 and Al2O3 which varied with the NaO2 content in the glass.