• 한국세라믹학회지
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• 제24권4호
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• pp.397-403
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• 1987

Pb(Zr0.52Ti0.48)O3 powders were prepared by hydrothermal synthesis. Using soluble salts such as Pb(NO3)2, TiCl4 and ZrOCl2$.$8H2O and oxide such as PbO and TiO2 as starting materials, PZT powder was hydrothermally synthesized at the temperature range between 150$^{\circ}C$ and 200$^{\circ}C$. The result showed that reactivity by alkali was decreased in the sequence of Pb(NO3)2, TiCl4, ZrOCl2, PbO, TiO2 and ZrO2. Using the first three soluble salts, PZT powder was synthesiged at 150$^{\circ}C$ for 1hr. In PbO-TiCl4-ZrOCl2 system, PZT powder was synthesized at 150$^{\circ}C$ for 8rs. In Pb(NO3)2-TiO2-ZrOCl2 system, PZT powder was synthesized at 150$^{\circ}C$ for 16hrs, in PbO-TiO2-ZrOCl2 system, the powder was synthesized at 200$^{\circ}C$ for 8hrs.

• 한국결정성장학회지
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• 제31권1호
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• pp.37-42
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• 2021

화학적 조성이 TiZrN 박막의 구조적 특성 및 열적 특성에 미치는 영향을 조사하였다. 증착된 TixZr1-xN(x = 0.87, 0.82, 0.7, 0.6, 0.28) 박막에서 Zr 분율이 증가함에 따라 결정립 크기가 감소하고 주상 구조에서 입계상 구조로 점진적으로 변화하는 미세구조 변화가 관찰되었다. 또한 XRD 분석을 통해 Zr 분율이 0.4까지 증가할 때 TiN 상에서 TiZrN 상으로의 점진적인 결정상 전이가 일어났음을 확인하였다. 900℃ 온도에서의 열처리 이후 Ti0.82Zr0.18N과 Ti0.7Zr0.3N 박막은 rutile 상 TiO2와 TiZrO4 산화물이 공존하는 형태로 전환된 반면에 Ti0.6Zr0.4N 박막은 TiZrO4 산화물로 변화함을 확인하였다. 다섯 가지 조성의 TiZrN 박막 중에서 Ti0.6Zr0.4N 박막이 가장 우수한 고온 안정성을 나타내었고, Inconel 617 기판의 열산화에 의해 발생하는 Cr의 표면 확산을 억제하는 열산화 저항성 향상 효과가 가장 우수함을 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2333-2337
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• 2007

Nanoporous TiO2 and ZrO2 thin films were spin-coated using a surfactant-templated approach from Pluronic P123 (EO20PO70EO20) as the templating agent, titanium alkoxide (Ti(OC4H9)4) as the inorganic precursor, and butanol as a the solvent. The control of the electronic structure of TiO2 is crucial for its various applications. We found that the band gap of the hybrid nanoporous thin films can be easily tuned by adding an acetylacetonestabilized Zr(OC4H9)4 precursor to the precursor solution of Ti(OC4H9)4. Pores with a diameter of 5 nm-10 nm were randomly dispersed and partially connected to each other inside the films. TiO2 and ZrO2 thin films have an anatase structure and tetragonal structure, respectively, while the TiO2-ZrO2 hybrid film exhibited no crystallinity. The refractive index was significantly changed by varying the atomic ratio of titanium to zirconium. The band gap for the nanoporous TiO2 was estimated to 3.43 eV and that for the TiO2-ZrO2 hybrid film was 3.61 eV.

• 한국세라믹학회지
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• 제34권6호
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• pp.583-590
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• 1997

The effects of Mn2O3 and Y2O3 additives on the microstructure and dielectric properties of Sr(Zr, Ti)O3 have been investigated. Powders with Sr(Zr1-xTix)O3(0$\leq$x$\leq$0.1) composition were prepared by the conventional solid state processing from commercial TiO2 and precipitation-processed ZrO2. The powders containing sintering additives of Mn2O3 and Y2O3 were compacted and then sintered at 1,55$0^{\circ}C$ for 4 h to get>97% relative density. Mn2O3 suppressed the grain growth and Y2O3 enhanced the density of sintered body. The oxidation state of Mn ions were determined by a chemical wet method and EPR spectroscopy. Mn ions were present as Mn2+ and Mn4+ in SrZrO3, while as Mn3+ and Mn4+ in Ti-substituted Sr(Zr, Ti)O3. With the substitution of Ti, the lattice parameters of SrZrO3 decreased and its dielectric constant increased with remarkable decrease in Q value. The dielectric constant of Sr(Zr, Ti)O3 was in the range of 30 to 40, Q values 1,200~5,400 at 6 GHz and temperature coefficient of resonant frequency -67~100 ppm/K.

• Bulletin of the Korean Chemical Society
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• 제29권6호
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• pp.1217-1223
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• 2008

A series of Zr,S co-doped $TiO_2$ were synthesized by a modified sol-gel method and characterized by various spectroscopic and analytical techniques. The presence of sulfur caused a red-shift in the absorption band of $TiO_2$. Co-doping of sulfur and zirconium (Zr-$TiO_2$-S) improves the surface properties such as surface area, pore volume, and pore diameter and also enhances the thermal stability of the anatase phase. The Zr-$TiO_2$-S systems are very effective visible-light active catalysts for the degradation of toluene. All reactions follow pseudo firstorder kinetics with the decomposition rate reaching as high as 77% within 4 h. The catalytic activity decreases in the following order: Zr-$TiO_2$-S >$TiO_2$-S >Zr-$TiO_2$>$TiO_2$$\approx$ P-25, demonstrating the synergic effect of codoping with zirconium and sulfur. When the comparison is made within the series of Zr-$TiO_2$-S, the catalytic performance is found to be a function of Zr-contents as follows: 3 wt % Zr-TiO2-S >0.5 wt % Zr-$TiO_2$-S> 5 wt % Zr-$TiO_2$-S >1 wt % Zr-$TiO_2$-S. Higher calcination temperature decreases the reactivity of Zr-$TiO_2$-S.

• 마이크로전자및패키징학회지
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• 제8권1호
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• pp.27-32
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• 2001

($Zr_{0.8}, Sn_{0.2})TiO_4$의 소결온도를 저하시키고 품질계수 향상의 목적으로 첨가한 $V_2O_5$가 다른 donor형태의 화합물과 달리 품질계수의 저하를 가져오는 원인을 $Ta_2O_5$가 첨가된 ($Zr_{0.8}, Sn_{0.2})TiO_4$와 미세 구조변화, 전기전도도, 산화상태의 관점에서 비교 분석하였다. 일반적으로 donor형태의 화합물의 첨가는 ($Zr_{0.8}, Sn_{0.2})TiO_4$의 산소공공의 농도를 감소시켜 품질계수의 증가를 가져오는 것으로 알려져 있다. $V_2O_5$의 첨가의 경우는 액상소결에 의한 결정입계상 존재, 섬유상 형태의 $V_2O_5-TiO_2$rich 이차상 형성 및 Vanadium 이온의 산화상태 불안정에서 기인된 산소공공의 농도 증가가 복합적으로 ($Zr_{0.8}, Sn_{0.2})TiO_4$의 품질계수 저하 요인으로 작용하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.197-197
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• 2008

There are fast growing demands for new dielectric materials for passive capacitors of RF-ICs and other wireless applications. One of the bulk microwave dielectric materials which have superior properties is $ZrTiO_4$ due to its large dielectric constant and high quality factor. Therefore, $ZrTiO_4$ is worth studying as a form of thin film to be applied for passive capacitors of integrated circuits. In this study, we fabricated metal-insulator-metal type capacitors with $ZrTiO_4$ dielectric thin film, and evaluated their capacitor properties.

• 한국결정성장학회지
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• 제18권1호
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• pp.5-9
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• 2008

코디어라이트는 낮은 열팽창계수를 가지나, 디젤 배기가스 담체로써 사용하기에는 기계적 강도가 낮고, 황에 대한 내산성이 취약한 문제를 가지고 있다. 본 연구에서는 $SiO_2,\;Al_2O_3$, MoOx, $Cr_2O_3$ 및 $Nb_2O_5$가 첨가된 $ZrTiO_4$의 물성을 XRD, SEM, UTM 및 열팽창계수 측정 장치를 사용하여 측정하고 분석하였다. $ZrTiO_4$은 $TiO_2$와 $ZrO_2$를 출발원료로 볼빌에서 혼합한 후 $1240^{\circ}C$ 이상의 온도에서 3시간 하소함으로써 monoclinic 구조로 합성되었다. 꺽임강도 및 열팽창계수 측정용 시편은 $ZrTiO_4$와 첨가제를 혼합 성형하고, $1300^{\circ}C$에서 3 시간 소성함으로써 얻어졌다. 소결된 시편의 기공율은 첨가제의 함량이 5%로 증가함에 따라 첨가제의 종류에 관계없이 감소하였으나, 첨가제의 함량이 10% 로 증가하면 기공율은 포화되었다. 꺾임강도는 $Al_2O_3$를 5, 10 wt% 첨가 시 큰 폭으로 증가하였으나, 나머지 첨가제에 대해서는 꺾임강도가 감소하였다. $ZrTiO_4$의 열팽창계수 $(1000^{\circ}C)$는 $Nb_2O_5$를 제외하고는 첨가제가 증가할수록 계속적으로 감소하였으며, 특히, $SiO_2$가 첨가된 경우 가장 낮은 열팽창계수를 나타내었다.

• 한국세라믹학회지
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• 제30권12호
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• pp.1023-1028
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• 1993

To obtain a single phase of Ba2Ti9O20 at lower temperature than previious other researches. We investigated the effect of Zr substitution for predetermined portions of Ti in Ba2Ti9O20. In this study, the four compounds(x=0, 0.028, 0.048, 0.068) of Ba2(Ti1-xZrx)9O20 were prepared by coprecipitation reaction of BaCl2, TiCl4 and ZrOCl2 with (NH4)2CO3 and NH4OH as the coprecipitating agents and pH regulators, in queous solution. Owing to 4.8 mol% addition, the single phase of Ba2Ti9O20 showing high Q was obtained at 115$0^{\circ}C$ which is lower by 25$0^{\circ}C$ than the temperature in case of mechanical mixtures of BaCO3 and TiO2.

• 한국세라믹학회지
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• 제31권8호
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• pp.835-840
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• 1994

In this study, the synthesis of Ba2Ti9O20 powder having chemically homogeneous and highly pure fine particle size distribution was attempted by the oxalate method. And the effects of ZrO2 addition was investigated. The four compositions (X=0, 0.028, 0.048, 0.068) of Ba2(Ti9-x, Zrx)O20 were prepared by precipitation reaction of BaCl2, TiCl4, and ZrOCl2, with oxalic acid and NH4OH acting as a precipitating agent and a pH regulator respectively, in aqueous solution. In case of 4.8 mol% ZrO2 addition, the single phase Ba2Ti9O20 was obtained at 120$0^{\circ}C$ and its dielectric properties was excellent showing K=40.5, Q=4621 at 5.4 GHz.