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        검색결과 7

        1.
        2009.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        SnxSe100-X (15|X|30) alloys have been studied to explore their suitability as phase change materials for nonvolatile memory applications. The phase change characteristics of thin films prepared by a Radio Frequency (RF) magnetron co-sputtering system were analyzed by an X-ray diffractometer and 4-point probe measurement. A phase change static tester was also used to determine their crystallization under the pulsed laser irradiation. X-ray diffraction measurements show that the transition in sheet resistance is accompanied by crystallization. The amorphous state showed sheet resistances five orders of magnitude higher than that of the crystalline state in SnxSe100-X (x = 15, 20, 25, 30) films. In the optimum composition, the minimum time of SnxSe100-X alloys for crystallization was 160, 140, 150, and 30ns at 15mW, respectively. The crystallization temperature and the minimum time for crystallization of thin films were increased by increasing the amount of Sn, which is correlated with the activation energy for crystallization.
        3,000원
        2.
        2009.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this report, the structural and optical properties of sol-gel derived MgxZn1-xO thin films upon changes in the composition and annealing temperature were investigated. The Mg2+ content and the annealing temperature were varied in the range of 0≤x≤0.35 and 400˚C≤T≤600˚C, respectively. The films exhibited a hexagonal wurtzite structure of a polycrystalline nature. The optical transmittance exceeded 85% and the optical band gap of the film was tuned as high as 3.84 eV at a value of x = 0.35 (annealed at 400˚C), which was evidently the maximum Mg2+ content for the single-phase polycrystalline MgxZn1-xO thin films prepared in this experiment. The optical band gap and photoluminescence emission were tailored to the higher energy side while maintaining crystallinity without a significant change of the lattice constant.
        4,000원
        3.
        2009.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The effect of annealing under argon atmosphere on hydrogenated amorphous silicon (a-Si:H) thin films deposited at room temperature and 300˚C using Radio Frequency (RF) magnetron sputtering has been investigated. For the films deposited at room temperature, there was not any increase in hydrogen content and optical band gap of the films, and as a result, quality of the films was not improved under any annealing conditions. For the films deposited at 300˚C, on the other hand, significant increases in hydrogen content and optical band gap were observed, whereas values of microstructure parameter and dark conductivity were decreased upon annealing below 300˚C. In this study, it was proposed that the Si-HX bonding strength is closely related to deposition temperature. Also, the improvement in optical, electrical and structural properties of the films deposited at 300˚C was originated from thermally activated hydrogen bubbles, which were initially trapped at microvoids in the films.
        4,000원
        4.
        2008.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The effects of the deposition and annealing temperature on the structural, electrical and opticalproperties of Ag doped ZnO (ZnO:Ag) thin films were investigated. All of the films were deposited with a 2wt%Ag2O-doped ZnO target using an e-beam evaporator. The substrate temperature varied from room temperature(RT) to 250oC. An undoped ZnO thin film was also fabricated at 150oC as a reference. The as-grown films wereannealed in temperatures ranging from 350 to 650oC for 5h in air. The Ag content in the film decreased asthe deposition and the post-annealing temperature increased due to the evaporation of the Ag in the film.During the annealing process, grain growth occurred, as confirmed from XRD and SEM results. The as-grownfilm deposited at RT showed n-type conduction; however, the films deposited at higher temperatures showedp-type conduction. The films fabricated at 150oC revealed the highest hole concentration of 3.98×1019cm-3 anda resistivity of 0.347Ω·cm. The RT PL spectra of the as-grown ZnO:Ag films exhibited very weak emissionintensity compared to undoped ZnO; moreover, the emission intensities became stronger as the annealingtemperature increased with two main emission bands of near band-edge UV and defect-related greenluminescence exhibited. The film deposited at 150oC and annealed at 350oC exhibited the lowest value of Ivis/Iuv of 0.05.
        4,000원
        5.
        2008.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Electrical optical switching and structural transformation of Ge15Sb85, Sb65Se35 and N2.0 sccm doped Sb83Si17 were studied to investigate the phase change characteristics for PRAM application. Sb-based materials were deposited by a RF magnetron co-sputtering system and the phase change characteristics were analyzed using an X-ray diffractometer (XRD), a static tester and a four-point probe. Doping Ge, Se or Si atoms reinforced the amorphous stability of the Sb-based materials, which affected the switching characteristics. The crystallization temperature of the Sb-based materials increased as the concentration of the Ge, Se or Si increased. The minimum time of Ge15Sb85, Sb65Se35 and N2.0 sccm doped Sb83Si17 for crystallization was 120, 50 and 90 ns at 12 mW, respectively. Sb65Se35 was crystallized at 170˚C. In addition, the difference in the sheet resistances between amorphous and crystalline states was higher than 104Ω/γ.
        3,000원
        6.
        2009.06 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study evaluated the immunoregulatory effect of phellinus linteus ethanol (PLE) extracts on liver damage on carbon tetrachloride (CCl4) induced in rats. Four-week old Male Sprague-Dawley rats were divided into the three experimental groups randomly; Control group, CCl4 group, CCl4 + PLE group. We found that effect of PLE on IFN-γ, STAT1 and pSTAT1 was decrease in vivo. Several genes were demonstrated to be IL-4 inducible prior to the discovery of STAT6. IL-4, STAT6 and pSTAT6 decreased significantly lower in CCl4 + PLE than the CCl4 group. Our data indicated that cytokine protein production were increased in CCl4 group with CCl4 + PLE group. In our data indicate that IgA levels in MLN lymphocytes were low, while IgE was high in CCl4 + PLE group compared with CCl4 group. Therefore, the results of this study show that PLE can be proposed to protect the liver against CCl4-induced immunoregulatory activity in rats.
        7.
        2009.04 KCI 등재 서비스 종료(열람 제한)
        The present study describes the preliminary evaluation of the anti-inflammatory activities of Phellinus linteus (PL) and Phellinus linteus Grow in Germinated Brown Rice (BRPL). In order to effectively screen for anti-inflammatory agents, we first examined the extracts' inhibitory effects on the expression of pro-inflammatory cytokines activated with lipopolysaccharide. Moreover, we examined the inhibitory effects of the PL and BRPL extracts on pro-inflammatory factors such as NO, iNOS, TNF-α and IFN-γ in murine macrophage RAW 264.7 cells. NO production and iNOS expression was significantly augmented in LPS treated cell, the production of NO and iNOS was greater in the BRPL than in the PL group. In addition, protein and mRNA levels of TNF-α and IFN-γ in BRPL showed relatively more potent pro-inflammatory-activity inhibition compared to that of PL. These results suggest that BRPL may have significant effects on inflammatory factors, and may be a potential anti-inflammatory therapeutic materials.