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        검색결과 3

        1.
        2010.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The usual ceramic process of mixing and milling in state of oxides ZrO2 and CeO2 was adopted in this study in a wet process to manufacture Ce-TZP. CeO2-ZrO2 ceramics containing 8~20 mol% CeO2 were made by heat treatment at 1250~1500˚C for 5hr. The maximum dispersion point of every slurry manufactured with a mixture of ZrO2 and CeO2 was neat at pH10. A stable slurry with average particle size of 90 nm can be manufactured when it is dispersed with the use of ammonia water and polycarboxylic acid ammonium. The sintered Ce-TZP ceramics manufactured with the addition of CeO2 in a concentration of less than 10 mol% progressed to the fracture of the specimen due to the existence of a monoclinic phase of more than 30% at room temperature. More than 99% of the tetragonal phase was created for the sintered body with the addition of CeO2 beyond 18 mol%, but the degradation of the mechanical properties on the entire specimen was brought about due to the CeO2 existing in a percentage above 3%. Consequently, the optimal Ce-TZP level combined in the oxide state was identified to be 16 mol% of CeO2 contents.
        4,000원
        2.
        2008.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Tetragonal-Ni1-xPdxSi/Si (001) structure was studied by using density functional theory (DFT). An epitaxial interface between 2×2×4 (001) tetragonal-NiSi supercell and 1×1×2 (001) Si supercell was first constructed by adjusting the lattice parameters of B2-NiSi structure to match those of the Si structure. We chose Ni atoms as a terminating layer of the B2-NiSi; the equilibrium gap between the tetragonal-NiSi and Si was calculated to be 1.1 Å. The Ni atoms in the structure moved away from the original positions along the z-direction in a systematic way during the energy minimization. Two different Ni sites were identified at the interface and the bulk, respectively. The two Ni sites at the interface have 6 and 7 coordination numbers. The Ni sites with coordination number 6 at the interface were located farther away from the interface, and were more favorable for Pd substitution.
        3,000원
        3.
        1992.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        2mol%의 이트리아로 안정화된 정방정상 지르코니아 분말을 800˚C부터 1500˚C 까지 온도별로 열처리하여 분말내 입자크기 및 입자간에 존재하는 구속력을 변화시킨 다음, 정방정상의 전이도 및 안정화효과가 무열상전이, 응력유기상전이, 등온상전이 에 미치는 영향을 고찰하였다. 그 결과 Y-TZP 분말내 정 방정상의 전이도는 고용체의 양이 일정할 경우 열처리온도의 변화에 따른 입자크기와 입자간에 존재하는 구속력의 크기에 의존하였는데 열처리온도가 증가함에 따라 전이도가 점차 증가하여 1300˚C로 열처리한 분말에서 최대값을 보였다. 그러나 1300˚C 이상으로 열처리한 분말에서는 열처리온도가 증가함에 따라 구속효과의 증가에 따라 전이도가 정차로 감소하였다. 전이도가 큰 분말에서는 정방정상이 무열상전이, 응력유기상전이, 등온상전이를 쉽게 일으켜 단사정상으로 전이하였다.
        4,000원