http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
RF magnetron 스퍼터링과 급속 열처리에 의한$YBa_2Cu_3O_{7-x}$
신현용 한국전기전자재료학회 1993 電氣電子材料學會誌 Vol.6 No.4
본 연구에서는 rf magnetron 스퍼터링으로 (100) 사파이어 기판에 퇴적시킨 YBa$_{2}$Cu$_{3}$$O_{7-x}$박막을 열처리하기 위하여 급속 열처리 방법을 사용하였다. XRD, AES, 그리고 4단자 비저항 측정법을 사용하여 급속 열처리로 형성시킨 초전도체 박막과 기판사이의 상호확산을 조사하였다. 제조된 박막은 91K에서 Tc(onset)를 80K에서 Tc(zero)를 나타내었다. AES 분석 결과, 급속 열처리 방법의 경우 YBa$_{2}$Cu$_{3}$$O_{7-x}$ HTS 박막과 기판사이의 계면에서 항호확산이 감소되는 것을 확인하였다. XRD 분석 결과, 급속 열처리에 의해 형성된 HTS 박막은 주로 c-축이 기판의 표면에 수직인 구조를 가지고 있었다.
Sol-gel법에 의한 Pb(Zr_0.52Ti_0.48)O_3 박막의 강유전 특성
신현용 남서울대학교 1995 남서울대학교 논문집 Vol.1 No.-
Pb(Zr_0.52Ti_0.48)O_3 ferroelectric thin films were fabricated on Pt/SiO_2/Si substrates by sol-gel processing and rapid thermal annealing. The hysteresis characteristics of the PZT films with platinum, silver, and aluminum as upper electrodes was examined. While the PZT thin films with silver electrodes deposited at 150 ℃ of substrate temperature showed excellent ferroelectric characteristics, the PZT films with silver electrodes deposited at ambient substrate temperature exhibited decreased remnant polarization and asymmetric hysteresis curves. The remnant polarization was decreased and the coercive field was increased as the film thickness decreased. PZT films thicker than 0.5 ㎛ with platinum electrodes showed superior characteristics over the films with silver electrods, while 0.28 ㎛ PZT films with silver electrodes showed better characteristics than the ones with platinum electrodes. The 0.28 ㎛ PZT films with silver electrodes and platinum electrodes showed the coercive fields of 39.9 ㎸/㎝ and 67.9 ㎸/㎝, the remnant polarization of 21.1 μC/㎠ and 20.1 μC/㎠, and the switching voltage of V_p = 6 V and V_p = 8 V, respectively.
신현용,Shin, Hyun-Yong 한국컴퓨터산업학회 2005 컴퓨터産業敎育學會論文誌 Vol.6 No.5
형광램프용 전자식 안정기의 효율개선 및 램프의 수명연장을 위하여 강유전체 커패시터와 시간지연스위칭회로로 구성된 절전모듈을 개발하고 적용하였다. 절전모듈에 사용된 강유전체 세라믹스를 이용하여 형광램프의 부저항특성과 최적화를 시키고, 시간지연회로를 통하여 점등초기 예열형에서 비예열형으로 스위칭시켜 점등 중 필라멘트에서 소비되는 전력을 제거함으로써 약 2W의 소비전력을 감소시켜 효율개선을 실현하였으며, 역기전력 제거기능을 통하여 점등 초기 형광램프 필라멘트에 가해지는 충격을 최소화함으로써 형광램프의 수명을 연장시켰다. Power saving module which is consisted of ferroelectric ceramic capacitor and time delay switching circuit was installed into electronic ballast in order to enhance energy efficacy and extend life time of fluorescent lamp. The impedance matching of negative resistance characteristics of F/L was optimized with the characteristics of ferroelectric ceramics capacitor to increase the light efficiency of the electronic ballast. The high efficiency of the electronic ballast was achieved by minimizing wasted power at the filament of F/L during the lighting by using the switching function of time delay circuit from preheating mode to non-preheating mode. The life time of F/L was also extended by eliminating the reverse electromotive force using time delay circuits to minimize the impacts to the filament of F/L from unwanted high voltage peaks during light-up period. As the results, the electronic ballast with the first grade energy efficiency was developed using ferroelectric ceramics and time delay module.
기사광선 펄스 레이저에 의해 제작된 $YBa_2{Cu_3}O_{7-X}$초전도체 박막의 특성
신현용 한국전기전자재료학회 1994 電氣電子材料學會誌 Vol.7 No.4
Thin films of YB $a_{2}$C $u_{3}$$O_{7-x}$ supercondYB $a_{2}$C $u_{3}$$O_{7-x}$uctor were prepared on (100) SrTi $O_{3}$ substrates by pulsed laser deposition using visible light laser. Q-switched Nd:YAG(532 nm, 30 ns) pulsed laser was used for deposition. The effects of substrate temperature and oxygen pressure during deposition on films were studied. Critical current density of 2.93*10$^{6}$ A/c $m^{2}$ at 77K and Tc(zero)=91.7K were obtained from the film prepared with Tsub=745.deg. C and $P_{02}$=200 mTorr. XRD analysis showed that the grown film has c-axis normal orientation to the substrate surface and has single phase. Surface morphology of the film has been improved by interfering the plume ejected from YB $a_{2}$C $u_{3}$$O_{7-x}$ target.arget.t.
기판온도와 후열처리가 PLD로 제조된 PZT 박막의 특성에 미치는 영향
신현용 남서울대학교 공학연구센터 2002 공학연구 Vol.3 No.-
The Effects of substrate temperature and post-annealing process on the structural and electrical properties of PbZr_052Ti_048O_3 (PZT) thin films prepared by Pulsed Laser Deposition (PLD) were investigated using XRD, SEM, and electrical hysteresis curves. The films deposited at the substrate temperature above 500℃ showed perovskite structure showing (110) preferential orientation perpendicular to the substrate without post-annealing process. The films prepared at the temperature below 450℃ changed from pyrochlore phase to perovskite phase through the post-annealing at 650℃ for 30 minutes. The PZT thin films deposited at 500℃ and post-annealed at 650℃ for 30 min. showed the excellent ferroelectric characteristics with remnant polarization of 42.32μC/㎠ and coercive filed of 70.80kV/cm.
급속 열처리 조건에 따른 Pb(Zr_0.52Ti_0.48)O_3 박막의 전기적 특성 변화
신현용,백동수 남서울대학교 1996 남서울대학교 논문집 Vol.2 No.-
Pb(Zr_0.52Ti_0.48)O_3∼Pb(10wt%) stock solution prepared by sol-gel processing was spin-coated on Pt/SiO_2/Si substrate and annealed by rapid thermal annealing to fabricate Pb(Zr_0.52Ti_0.48)O_3 ferroelectric thin films. Annealing temperature was changed from 550 ℃ to 750 ℃ and the annealing time was varied from 10 seconds to 120 seconds to observe their effects on the characteristics of the films. The films annealed at 650t! for 20 seconds showed dielectric constant of 1550 and dielectric loss(tanδ) of 0.02. However, dielectric constant and tan6 of the films annealed at 550℃ for 20 seconds showed severely deteriorated values of 840 and 0.04, respectively. Coercive field and remnant polarization of the films annealed at 650 ℃ for 20 seconds were 32㎸/㎝ and 29μC/㎠, respectively, and irrelevant to the annealing time longer than 20 seconds. Dielectric constant of the films annealed at 650℃ for 20 seconds was increased as the film thickness increased and the value was about 1550∼1600 for the films thicker than or equal to 0.7㎛ in thickness. The deviation of dielectric constant of 0.7㎛ film was within 4% over the area of 15 × 15㎟.