간행물
한국재료학회지 KCI 등재 SCOPUS Korean Journal of Materials Research
- 발행기관 한국재료학회
- 자료유형 학술지
- 간기 월간
- ISSN 2799-8525 (Print)2799-8681 (Online)
- 수록기간 1991 ~ 2024
- 주제분류 공학 > 재료공학 공학 분류의 다른 간행물
- 십진분류KDC 530DDC 620
권호리스트/논문검색
제18권 제2호 (2008년 2월) 10건
1.
2008.02
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
2.
2008.02
구독 인증기관 무료, 개인회원 유료
The present work was performed to investigate the effect of coiling temperature on the annealed texture in Cu/Nb-added ultra-low-carbon steels. The ultra-low-carbon steels were coiled at 650 and 720˚C, respectively. The result showed that the Cu-added ultra-low-carbon steel at a low coiling temperature produced a desirable annealed texture related to good formability. On the other hand, Nb-added ultra-low-carbon steel at a high coiling temperature also produced a desirable texture. This is attributed to the effect of Nb, which retards recrystallization during the coiling process.
3,000원
3.
2008.02
구독 인증기관 무료, 개인회원 유료
A sensor element array for combinatorial solution deposition research was fabricated using LTCC (Low-temperature Co-fired Ceramics). The designed LTCC was co-fired at 800˚C for 1 hour after lamination at 70˚C under 3000 psi for 30 minutes. SnO2 sol was prepared by a hydrothermal method at 200˚C for 3 hours. Tin chloride and ammonium carbonate were used as raw materials and the ammonia solution was added to a Teflon jar. 20 droplets of SnO2 sol were deposited onto a LTCC sensor element and this was heat treated at 600˚C for 5 hours. The gas sensitivity (S = Ra/Rg) values of the SnO2 sensor and 0.04 wt% Pd-added SnO2 sensor were measured. The 0.04 wt% Pd-added SnO2 sensor showed higher sensitivity (S = 8.1) compared to the SnO2 sensor (S = 5.95) to 200 ppm CH3COCH3 at 400˚C.
3,000원
4.
2008.02
구독 인증기관 무료, 개인회원 유료
[ SF6 ] gas has been widely used as an insulating, cleaning and covering gas due to its outstanding insulating feature and because of its inert properties. However, the global warming potential of SF6 gas is extremely high relative to typical global warming gases such as CO2, CFCs, and CH4. For these reasons, it is necessary to separate and collect waste SF6 gas. In this study, the effects of a surfactant (Tween) on the formation rate of SF6 gas hydrates were investigated. The SF6 gas hydrate formation rate increased with the addition of Tween and showed a nearly 6.5 times faster hydrate formation rate with an addition of 0.2 wt.% Tween compared to an addition of pure water. This is believed to be due to the increased solubility of SF6 gas with the addition of the surfactant. It was also found that SF6 gas hydrate in the surfactant solution showed two-stage hydrate formation rates with a formation rate that increased rapidly in the 2nd stage.
3,000원
5.
2008.02
구독 인증기관 무료, 개인회원 유료
Green-emitting Ba1.468Sr0.5SiO4 : Eu0.012, Y0.02 phosphor powders under long-wavelength ultraviolet light were prepared via high-temperature flame spray pyrolysis from spray solutions with and without NH4Cl flux. The effects of the temperature of the diffusion flame and the NH4Cl flux on the morphologies, crystal structures and photoluminescence intensities of the Ba1.468Sr0.5SiO4 : Eu0.012, Y0.02 phosphor powders were investigated. The phosphor powders obtained from the spray solution with the NH4Cl flux had higher photoluminescence intensities compared to phosphor powders obtained from the spray solution without the flux. The photoluminescence intensity of the phosphor powders obtained from the spray solution without the flux decreased as the flow rate of the fuel gas increased. On the other hand, the photoluminescence intensity of the phosphor powders obtained from the spray solution with the flux increased as the flow rate of the fuel gas increased. The difference of in the phase purity and morphology of the powders affected the photoluminescence intensities of the phosphor powders.
4,000원
6.
2008.02
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
7.
2008.02
구독 인증기관 무료, 개인회원 유료
In spray pyrolysis, the effects of the preparation temperature, flow rate of the carrier gas and concentration of the spray solution on characteristics such as the morphology, size, and emission intensity of Ca8Mg(SiO4)4Cl2:Eu2+ phosphor powders under long-wavelength ultraviolet light were investigated. The phosphor powders obtained post-treatment had a range of micron sizes with regular morphologies. However, the composition, crystal structure and photoluminescence intensity of the phosphor powders were affected by the preparation conditions of the precursor powders. The Ca8Mg(SiO4)4Cl2:Eu2+ phosphor powders prepared at temperatures that were lower and higher than 700˚C had low photoluminescence intensities due to deficiencies related to the of Cl component. The phosphor powders with the deficient Cl component had impurity peaks of Ca2SiO4. The optimum flow rates of the carrier gas in the preparation of the Ca8Mg(SiO4)4Cl2:Eu2+ phosphor powders with high photoluminescence intensities and regular morphologies were between 40 and 60 l/minute. Phosphor powders prepared from a spray solution above 0.5 M had regular morphologies and high photoluminescence intensities.
4,000원
8.
2008.02
구독 인증기관 무료, 개인회원 유료
The ferroelectric properties of UV irradiated and non-irradiated PZT films prepared via photochemical metal-organic deposition using photosensitive precursors were characterized. Fourier transform infrared spectroscopy showed that complete removal of organic groups was possible through UV exposure of the spin-coated PZT precursor films at room temperature. The measured remnant polarization values of UV-irradiated and non-irradiated PZT films after annealing at 650˚C were 29 and 23 μC/cm2, respectively. The UV irradiation was found to be effective for the enhancement of the<111> growth orientation and ferroelectric property of PZT film and in the direct patterning in the fabrication of micro-patterned systems without dry etching.
4,000원
9.
2008.02
구독 인증기관 무료, 개인회원 유료
The magneto-transport properties of an individual single crystalline Bi nanowire grown by aspontaneous growth method are reported. A four-terminal device based on an individual 400-nm-diameternanowire was successfully fabricated using a plasma etching technique that removed an oxide layer that hadformed on the surface of the nanowire. Large transverse ordinary magnetoresistance (1401%) and negativelongitudinal ordinary magnetoresistance (−38%) were measured at 2K. It was observed that the period ofShubnikov-de Haas oscillations in transverse geometry was 0.074T−1, 0.16T−1 and 0.77T−1, which is in goodagreement with those of bulk Bi. However, it was found that the period of SdH oscillation in longitudinalgeometry is 0.24T−1, which is larger than the value of 0.16T−1 reported for bulk Bi. The deviation is attributableto the spatial confinement arising from scattering at the nanowire surface boundary.
3,000원
10.
2008.02
구독 인증기관 무료, 개인회원 유료
[ BaO·Nd2O3·5TiO2 ] (BNT) ceramics modified with a borate glass containing Ba, Nd and Ti as glass constituents were investigated with regard to their sintering behavior and microwave dielectric properties. An addition of iso-component glass significantly improved the sinterabilty of the BNT ceramics and lowered the sintering temperature. A maximum density of 5.29 g/cm3 and an x-y shrinkage of 17% were obtained for BNT ceramics containing 10wt.% of the glass sintered at 1100˚C. The dielectric composition without the glass additive was only slightly densified at 1100˚C. The resulting sample exhibited two crystalline phases, BaNd2Ti5O14 and Ba2Ti9O20, regardless of sintering temperature and glass content. When >10wt.% glass was added, exaggerated grain growth with a less uniform microstructure was found, resulting in the subsequent reduction of the fired density and the dielectric properties. BNT ceramics containing 10wt.% of the isocomponent glass sintered at 1100˚C for 4 h showed promising dielectric properties of k = 71.3 and Q = 1,330.
4,000원
