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        검색결과 3

        2.
        1993.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Bi-Sr-Ca-O 초전도성계에서 Bi2O3-(Sr2CaCu2Ox)의 pseude binary계를 선택하여 Sr2CaCu2Ox에 Bi2O3를 5%단위로 40 cation mole% Bi까지 첨가하면서 850˚C 초전도상 및 공존하는 상들의 평형 및 반응 경로들을 XRD, SEM, EDS, DTA를 이용하여 분석하였다. Bi의 함량이 35 mole% Bi보다 클 때에는 Bi2Sr2CaCu2O8상과 공존하는 액상이 형성되며 2212상의 액상으로 존재하며 액상의 냉각시 제일 먼저 Bi2Sr2CaCu2O8상 주의에 석출된 것이 관찰되었다.
        4,300원
        3.
        1998.12 KCI 등재 서비스 종료(열람 제한)
        Crystallization behavior of platinum minerals within Pt-Sb-Bi bearing ore magmas and mineralogical properties of the existing minerals were investigated at 1,000℃ by synthetic experiment. High purity reagents were used as starting materials and silica tubings as containers. Reaction products were analysed by reflecting microscopy, X-ray diffraction, electron probe microanalysis, and micro-hardness test. Stable minerals at 1,000℃ are platinum, electron probe microanalysis, and micro-hardness test. Stable minerals at 1,000℃ are platinum, stump-flite (PtSb) and geversite (PtSb2). They are in equilibrium with liquid (ore magma). Platinum contains considerable amount of Sb of 7.5 at.%, whereas Bi only up to 0.9 at.%. Pure stumpflite is hexagonal with space group P63/mmc, and unit cell parameters are a=4.1318(6), c=5.483(1)a. VHN50=417(2)a. Geversite has cubic structure with space group Pa3. Cell parameters are a=6.4373(2)a and Vicker hardness values VHN50=663.5 (566~766). Both stumpflite and geversite show solid solution and their end-members are Pt48.8Sb40.7-Bi10.5, and Pt33.7-Sb59.8Bi6.5, respectively. Although stumpflite (m.p. 1,043℃) and unnamed PtBi (m.p. 765℃) do not form a complete solid solution at 1,000℃, they are known, at 600℃, to form a continuous solid solution. Geversit (m.p. 1,226℃) also forms complete solid solution with insizwaite (m.p. 660℃). Unit cell dimensions of the minerals above increases with the amount of Bi substituting for Sb.