• 한국세라믹학회지
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• 제35권7호
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• pp.665-670
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• 1998

Ferroelectric anomaly in PbO-{{{{ { {B }_{2 }O }_{3 } }}-{{{{ {TiO }_{3 } }}-BaO glasses which is observed in DAT measurements was in-vestigated together with the effect of BaO content on the shift of Cuire temperature. The temperature where the ferroelectric anomaly apperars on cooling in DTA decreased in proportion with increasing BaO content,. For as-crystallized samples the ferroelectric anomaly was not observed on heating but on cooling whilist for powder samples leached chemically from the crystallized samples both endothermic and ex-otehrmic peaks were observed. This fact suggests that the appearance of the ferroelectric anomaly in DAT largely depends on glassy phases surrounding individual {{{{ {PbTiO }_{3 } }} crystals rather than effects of grain size and crystallinity.

• 한국결정성장학회지
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• 제10권6호
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• pp.418-424
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• 2000

sol-gel 방법으로 순수한 $TiO_2$와 Pb가 10 mol % 첨가된 $TiO_2(Pb_xTi_{1-x}O_2$(x = 0.1)) 분말과 박막을 제조하였다. $TiO_2$제조에는 titanium isopropoxide와 ethanol이 $Pb_xT_{1-x}O_2$(x = 0.1) 제조에는 lead acetate trihydrate와 titanium triisopropoxide monoacethylacetonate이 사용되었다. P-type Si(100) wafer, ITO glass 기판 위에 sol-gel spin-coating방법으로 박막을 형성시켰으며 상(phase)의 형성과 결정화를 위해서 400~$800^{\circ}C$에서 열처리하였다 준비된 분말 및 박막의 특성은 TGA/DTA, XRD, SEM, UV-visible spectrometer를 이용하여 검토하였다. XBD 측정 결과 A(101)면으로 우선 배향된 다결정성 anatase 형의 분말 및 박막을 얻을 수 있었고 Pb가 첨가된 박막에 대한 d-값의 작은 변화가 관측되었는데 이는 Pb가 $TiO_2$살창으로 들어왔음을 의미한다. UV-visible투과 스펙트럼측정 결과에 의하면 Pb가 첨가된 박막에서 투과 스펙트럼의 흡수파장이 장파장쪽으로 이동하는데 이는 Pb가 첨가되면 밴드 갭의 축소가 일어남을 의미한다.

• 대한전기학회논문지
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• 제41권8호
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• pp.858-868
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• 1992

0.085Ba(LaS11/2TNbS11/2T)OS13T-0.915Pb(ZrS1yTTiS11-yT)OS13T (0.45$\leq$y$\leq$0.65) transparent electrooptic ceramics were fabricated by two-stage sintering method. The structural, ferroelectric and electrooptic properties were investigated varying composition and second sintering time. Also the possibility of application to electrooptic device was studied. If we increase the PbZrOS13T contents, dielectric constants were increased and Curie temperature was decreased. In the composition of 0.55[mol] PbZrOS13T, electromechanical coupling factor and piezoelectric charge constant were the highest values of 43[%] and 173x10S0-12T[C/N], respectively. Mechanical quality factors were decreased with the increasing PbZrOS13T contents. Light transmittance was increased with wavelength when measured from 300[nm] to 900[nm], and with PbZrOS13T contents in the range of 0.50[mol]-0.65[mol], and had the highest value of 67[%] in the composition of 0.65[mol] PbZrOS13T. From the results of ferroelectric hysteresis loop and transmitted light intensity with electric field, the specimens with compositions of 0.65,0.60,0.55[mol] PbZrOS13T were applicable to electrooptic memory device and those with compositions of 0.50,0.45[mol] PbZrOS13T were applicable to linear electrooptic device.

• E2M - 전기 전자와 첨단 소재
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• 제10권2호
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• pp.134-140
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• 1997

PbTiO$_{3}$-PbZrO$_{3}$-Pb(Ni$_{1}$3/Nb $_{2}$3/O$_{3}$)(PZT-PNN) thin films were prepared from corresponding metal organics partially stabilized with diethanolamine by the sol-gel spin coating method. Each mol rates of PT:PZ:PNN solutions were #1(50:40:10), #2(50:30:20), #3(45:35:20) and #4(40:40:20), respectively. The spin-coated PZT-PNN films were sintered at the temperature from 500.deg. C to 600.deg. C for crystallization. The P-E hysteresis curve was drawn by Sawyer-Tower circuit with PZT-PNN film. The coercive field and the remanent polarization of #4(40:40:20 mol%) PZT-PNN film were 28.8 kV/cm and 18.3 .mu.C/cm$^{2}$, respectively. Their dielectric constants were shown between 128 and 1120, and became maximum value in MPB(40:40:20 mol%). The leakage currents of PZT-PNN films were about 9.4x 10$^{-8}$ A/cm$^{2}$, and the breakdown voltages were about 0.14 and 1.1 MV/cm. The Curie point of #3(45:35:20 mol%, sintered at 600.deg. C) film was 330.deg. C.

• 한국세라믹학회지
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• 제31권6호
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• pp.581-586
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• 1994

Effect of excess and deficiency of PbO on the sintering and electrical properties of tetragonal Pb(Zr0.5Ti0.5)O3 were investigated. Fired density revealed maximum value with 4 wt% of excess PbO, and decreased with increasing amount of both excess and deficient PbO. Grain size increased with excess PbO, and decreased with deficiency of PbO. It appeared that excess PbO forms a liquid phase to enhance grain growth and completely volatilizes after sintering, whereas ZrO2 particles formed in PbO-deficient PZT inhibit grain growth. The change in the values of the equivalent circuit elements of PZT corresponded well with thar of porosity formed by excess and deficiency of PbO; kp, Co and Cm decreased while Qm, Rm and Lm increased conosiderably with porosity. This change was more pronounced in PbO-deficient type probably due to change in Zr/Ti ratio of PZT.

• 한국결정성장학회지
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• 제2권2호
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• pp.71-76
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• 1992

$0.05Pb(Al_{2/3}W_{1/3})O_3-0.95Pb(Zr_{0.52}Ti0.48)O_3$를 기본 조성으로 $MnO_2,Fe_2O_3$를 첨가제로 하여 사진식각법(Photolithography)을 이용 세라믹 필터를 제작하였다. $MnO_2$의 첨가량이 증가함에 따라 전기 기계 결합 계수(Kp)가 낮아지며, $Fe_2O_3$의 경우 Kp값은 57% 정도로 우수하나 기계적 품질 계수(Qm)는 $MnO_2$첨가의 경우에 비해 상대적으로 낮은 값을 보여주고 있다. $MnO_2$0.3wt% 첨가의 경우 3dB 대역폭은 155kHz, $ Fe_2O_3$0.1wt%인 경우 260kHz로써 Qmr값이 크기에 반비례하였으며, 군지연시간 특성은 $MnO_2$의 경우 Gaussian 특성을,$Fe_2O_3$의 경우 Butterworth 특성을 나타내었다.

• E2M - 전기 전자와 첨단 소재
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• 제1권2호
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• pp.152-161
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• 1988

Pb(Zr, Ti)O$^{3}$-Pb(Mg, Nb)O$^{3}$계에 MnO$_{2}$첨가량을 변화시켜 소결성, 미세구조, 유전상수, 비저항 및 압전특성에 미치는 영향을 XRD, EDAX 및 SEM을 이용하여 미세구조를 관찰하고 실험을 통하여 전기적 성질에 미치는 영향을 밝혔다. 비저항의 변화없이 그레인 성장이 억제되는 $MnO_{2}$의 첨가량은 0.4wt%이었으며 이때 분말의 합성이 촉진되어 소성된 시편의 밀도가 증가하였다. 그러나 고상반응의 범위를 벗어나는 과잉 $MnO_{2}$는 편석이 되어 그레인 경계상에 모임이 확인되었고 또한 기공을 형성하여 밀도를 낮추었다. $Mn^{+4}$는 $Mg^{+2}$ 와 치환되어 페로브스카이트 구조의 "A" 결핍을 유발하였으며 이것이 비저강을 감소시키는 원인으로 밝혀졌다.감소시키는 원인으로 밝혀졌다.

• 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.

• The Korean Journal of Ceramics
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• 제4권4호
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• pp.286-291
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• 1998

Dielectric properties of $Pb(Mg_{1/3}Nb_{2/3})O_{3}-PbTiO_{3}$, ceramics prepared by the columbite precursor method have been investigated as a function of the sintering temperature in the range of 1000∼$1250^{\circ}C$. The $Pb(Mg_{1/3}Nb_{2/3})O_{3}-PbTiO_{3}$ ceramics show typical relaxor ferroelectric behavior. As the sintering temperature increased, the dielectric constant increased and the phase transition temperature shifted to lower temperature. The TCK(temperature coefficient of dielectric constant) and VRK (variation rate of dielectric constant) increased with increasing sintering temperature. The $Pb(Mg_{1/3}Nb_{2/3})O_{3}-PbTiO_{3}$ compositions sintered at $1250^{\circ}C$ appear to be suitable for ferroelectric bolometer.

• E2M - 전기 전자와 첨단 소재
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• 제6권3호
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• pp.241-247
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• 1993

본 연구에서는 투광성 0.085Ba(L $a_{1}$2/N $b_{1}$2/) $O_{3}$- 0.915Pb(Z $r_{y}$ $Ti_{1-y}$) $O_{3}$(0.45.leq.y.leq.0.70)세라믹을 2단 소성법으로 제작한 후, PbZr $O_{3}$조성 및 온도에 따른 구조적, 강유전적특성을 측정하였다. XRD측정 결과, PbZr $O_{3}$조성이 감소할수록 결자상수 및 단위격자 체적은 감소하였으며 시편의 결정구조는 입방정계에서 능면체정계, 정방정계로 변화되었다. 8.5/60/40시편의 경우 포화분극, 잔류분극 및 항전계가 각각 33.28[.mu.C/$cm^{2}$], 4.15[kV/cm]로 전형적인 메모리 특성을 나타내었으며 PbZr $O_{3}$조성이 증가함에 따라 강유전 이력곡선은 slim loop특성을 나타내었다. 잔류분극은 온도가 증가함에 따라 감소하였으며 특히 PE-FE상경계 부근에 위치한 조성의 경우, 상전이 온도 이하의 온도에서 급격히 감소하는 경향을 나타내었다.다.