• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.251-251
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• 2007

A new type of a lead-free positive temperature coefficient of resistivity(PTCR) material. based on $(Bi_{1/2}Na_{1/2})TiO_3\;-\;BaTiO_3$ solid solution ceramics has been developed. The effect of $Nb_O_5$ and $Y_2O_3$ content on the electrical properties and the microstructure of (1-x) $(Bi_{1/2}Na_{1/2})TiO_3\;-\;x\;BaTiO_3$ (BNBT) ceramics made using a conventional mixed oxide process has been studied. The Curie Temperature was obviously increased with the increasing of $(B_{0.5}Na_{0.5})TiO_3$ content. The Y-doped BNBT ceramics(x=0.02) display low resistivity values of $10^2-10^3$ ohm*cm at room temperature and the Curie Temperature of $Tc=155^{\circ}C$.

• 분석과학
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• 제10권6호
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• pp.439-444
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• 1997

압전 세라믹스 [$Pb(ZrTi)O_3$] 소재에 대하여 신속하고 정확하게 분석할 수 있는 X-선 형광분석용 표준물질 12종을 제작하였다. 특히 매질효과의 제거, 보관성, 균질성 등을 고려하여 융제($Li_2B_4O_7/LiBO_2=4/1$)로 시료를 16배 희석하여 제작하였다. 네 곳의 분석기관에서 X-선 형광분광기로 12개의 표준물질에 포함된 11 원소에 대하여 검정곡선을 작성해 본 결과 PbO, $ZrO_2$, $TiO_2$, SrO, $WO_3$, $La_2O_3$, $Cr_2O_3$, MgO, $Nb_2O_5$, $MnO_2$들은 correlation factor가 0.998을 넘는 대단히 좋은 직선을 얻었다. 그러나 ZnO의 correlation factor는 0.977로 비교적 낮았으며, 이는 표준시료 중 ZnO의 함량이 10ppm 정도로 낮았기 때문이다. 본 연구에서 제작한 XRF 분석용 표준물질을 이용하면 PZT 중의 주 부성분 원소의 함량을 간편하고 신속 정확하게 분석결과를 얻을 수 있다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.549-552
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• 2002

$(SrBi_2Nb_2O_9)_{0.5}-(Bi_3TiNbO_9)_{0.5}$ ceramics were fabricated by the mixed-oxide method, and the structural and electrical properties with variation of ball-milling time were investigated. All SBN-BTN specimens showed the typical polycrystalline X-ray diffraction patterns without the presence of the second phase. The SBN-BTN specimen sintered at $1200^{\circ}C$ and ball-milled for 168h showed the average grain size of $16{\mu}m$. The dielectric constant and dielectric loss of the SBN-BTN specimen sintered at $1150^{\circ}C$ and ball-mill for 72h were 225, 0.4% at 1KHz, respectively.

• E2M - 전기 전자와 첨단 소재
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• 제10권5호
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• pp.434-439
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• 1997

It this paper, the piezoelectric and electro-induced strain properties of (P $b_{1-}$2x/3/B $i_{x}$ )[N $i_{1}$3/N $b_{2}$3/)$_{0.4}$( $Ti_{0.6}$Z $r_{0.4}$)$_{0.6}$] $O_3$ceramics (x=0, 0.005, 0.02) were investigated with the substitution of B $i^{3+}$, and the feasibility of the application for bimorph actuator was evaluated by measuring the dynamic properties of the piezoelectric bimorph fabricated with above ceramics. Dielectric constant was enhanced with the increase of B $i^{3+}$ substitution, and appeared the maximum value of 5032 at x=0.01 composition. Increasing the substitution of B $i^{3+}$, the electromechanical coefficient( $k_{p}$ , $k_{31}$ ) was increased up to the substitution of 0.5 mol% B $i^{3+}$, showed the value of 0.656, 0.439, respectively. The piezoelectric constant( $d_{33}$ $d_{31}$ ) had the highest value of 344, 825 with the substitution of 0.5 mol% B $i^{3+}$. The strain, generated by 60 Hz AC electric field, had the largest value of 1200($\times$10$^{-6}$ $\Delta$1/1) in the composition with the substitution of 0.5 mol% B $i^{3+}$. The dynamic properties of the bimorph actuator, fabricated with the composition substitution of 0.5 mol% B $i^{3+}$, showed the largest value of 325 $\mu$m at $\pm$150 V square pulse. square pulse.are pulse..

• Bulletin of the Korean Chemical Society
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• 제18권6호
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• pp.623-628
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• 1997

A layered perovskite oxide, $RbLa_2Ti_2NbO_{10}$, was prepared and investigated for proton exchange and intercalation behaviors. Its protonated form, $Hla_2Ti_2NbO_{10}$, exhibits the Bronsted acidity and reacts with organic amines. Polyoxonuclear cation, 4Al_{13}$, was then introduced into the interlayer by refluxing octylamine-intercalated compound with an $Al_{13}$ pillaring solution. These layered oxides were characterized by X-ray diffractometer, thermogravimeter, FT-infrared spectrometer and elemental analyzer. It is observed that the polyoxonuclear cation-pillared material exhibits a bilayer structure and is thermally more stable than organic counterpart at higher temperatures. The surface area of the pillared material annealed at 400 ℃ was the value of 25.1 m²/g.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.255-258
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• 2000

In this study, the structural, dielectric and piezoelectric properties of Pb[(Sb$\sub$1/2/Nb$\sub$1/2/)$\sub$x/- (Ni$\sub$1/3/Nb$\sub$2/3/)$\sub$0.15-x/- (Zr,Ti)$\sub$0.85/]O$_3$(x = 0, 0.01, 0.02, 0.03, 0.04, 0.05) ceramics is investigated as a function of Pb(Sb$\sub$1/2/Nb$\sub$1/2/)O$_3$ (abbreviated PSN) substitution. With the increase of PSN substitution, the crystal structure is transO$_3$formed from the tetragonal phase to the rhombohedral phase and the grain size is decreased abruptly. The curie temperature is decreased with the PSN substitution. The dielectric constant is increased with the PSN substitution and maximum value of 2290 is obtained at 4mol% PSN. With the PSN substitution, the coercive field is increased and the remnant polarization is decreased. The Electromechanical coupling factor(k$\sub$p/) Is showed the highest value of 0.622 at lmol% PSN and the mechanical quality factor(Q$\sub$m/) is decreased abruptly with the PSN substitution.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1993년도 추계학술대회 논문집
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• pp.10-13
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• 1993

ln this study, x PSN - y PT - z PZ ceramics doped with w MnO$_2$were fabricated by the mixed oxide method at 1250[$^{\circ}C$] for 2[hr] and then the dielectric and pyroelectric properties were investigated. In the 0.05 PSN - 0.4 PT - 0.55 PZ specimen with 0.5[wt.%] MnO$_2$, the pyroelectric coefficient was 6.6${\times}$10$\^$-8/[C/cm$^2$$.$$^{\circ}C$], respectibly.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.223-223
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• 1999

PZT(PbZr1-xTixO3) 박막은 고유전율과 같은 remanent polarization을 가져서 고집적 소자의 커패시터 유전율층 또는 비휘발성 메모리 소자의 제조에 이용되고 있으나, fatigue 와 aging 문제로 인하여 새로운 물질의 개발이 필요한데, 그 대표적으로 연구되고 있는 것이 PMN-PT(Pb(Mg1/3Nb2/3)O-PbTiO3) 이다. 본 실험에서는 sol-gel 법에 의하여 제조된 PMN-PT막을 ICP(Inductively coupled plasma)에 의하여 식각하였고 mask층으로는 PR을 사용하였다. 식각 가스로는 Ar, Cl, BCl를 단독 또는 혼합하여 사용하였으며, 식각 특성을 보기 위하여 RF Power, Substrate bias, Operation pressure, Substrate temperature를 변화시켰다. 식각속도는 stylus profiler를 이용하여 측정하였고, 단면 profile은 scanning electron microscopy (SEM)를 이용하여 관찰하였다. 식각 메커니즘을 규명하고자 식각된 박막의 표면을 X-ray photoelectron spectroscopy (XPS)로 관찰하였고, optical emission spectroscopy (OES)로 플라즈마 특성을 규명하고자 하였다. 식각속도는 Ar 또는 Cl2 플라즈마에 BCl3 가스를 혼합하였을 경우 증가되었고, BCl3 가스를 단독으로 사용하여도 높은 식각속도를 나타내었으며, BCl3의 첨가량이 늘어날수록 PR의 식각속도는 감소하여 높은 선택비를 보였다. 90% BCl3/10%Cl2 플라즈마에서 2800$\AA$/min의 식각속도 그리고 1.37:1의 PR 선택비를 얻을 수 있었다. Power나 기판 bias 증가에 따라 식각속도는 증가하였으나 기판 온도변화에는 민감하지 않았다. BCl3 rich에서의 식각속도 증가와 선택비 증가는 B2O3의 형성에 의한 것으로 생각된다.

• 한국전기전자재료학회논문지
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• 제23권10호
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• pp.771-775
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• 2010

In this study, piezoelectric and dielectric properties of the $(Na_{0.5}K_{0.5})NbO_3-(1-x)(Bi_{0.5}Na_{0.5})TiO_3-xBaTiO_3$ [NKN-(1-x)BNT-xBT] ceramics were investigated. The lead-free NKN-(1-x)BNT-xBT ceramics were fabricated by a conventional mixed oxide method. The results indicate that the addition of $BaTiO_3$ significantly influences the sintering, microstructure, phase transition and electrical properties of NKN-BNT ceramics. A gradual change in the piezoelectric and dielectric properties was observed with the increase of BT contents. The dielectric constant, piezoelectric constant ($d_{33}$) and electromechanical coupling factor ($k_p$) increased at the morphotropic phase boundary (MPB). The $d_{33}$=184 pC/N, $k_p$=0.38, dielectric constant=1455 with dielectric loss value of less than 1% were obtained for the NKN-0.95BNT-0.05BT ceramics sintered at $1150^{\circ}C$ for 2h. These results demonstrate that the NKN-(1-x)BNT-xBT ceramics is an attractive candidate for lead-free piezoelectric materials.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1496-1498
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• 1994

In this study, x PSN - y PT - z PZ ceramics doped with w $MnO_2$ were fabricated by the mixed oxide method at 1250 [$^{\circ}C$] for 2[hr] and then the dielectric and pyroelectric properties were investigated. In the 0.05 PSN - 0.4 PT - 0.55 PZ specimen with 0.5[wt%] $MnO_2$ the Pyroelectrics coefficient was $6.6{\times}10^{-8}[C/cm^2.^{\circ}C]$, respectibly.