• 한국전기전자재료학회논문지
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• 제18권1호
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• pp.57-61
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• 2005

The microwave dielectric properties of 0.6TiTe$_3$O$_{8}$-0.4MgTiO$_3$ ceramics with H$_3$BO$_3$-SnO were investigated to improve the sintering condition for the LTCC. According to the X-ray diffraction patterns, 0.6TiTe$_3$O$_{8}$-0.4MgTiO$_3$ ceramics with H$_3$BO$_3$-SnO had the columbite structure of TiTe$_3$O$_{8}$ phase and the ilmenite structure of MgTiO$_3$ phase and there were no second phase. Increasing the addition of H$_3$BO$_3$-SnO, the density and dielectric constant of the 0.6TiTe$_3$O$_{8}$-0.4MgTiO$_3$ ceramics were increased but the quality factor was decreased. The temperature coefficient of resonant frequency was shifted to the negative(-) direction with addition of H$_3$BO$_3$-SnO.EX>-SnO.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.169-170
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• 2008

In this study, low temperature sintering property of the $0.6TiTe_3O_8-0.4MgTiO_3$ ceramics with sintering adds were investigated for LTCC application which enable to cofiring with Ag electrode. $TiTe_3O_8$ mixed with $MgTiO_3$ to improve the temperature property. In the X-ray diffraction patterns, the columbite structure of $TiTe_3O_8$ phase and ilmenite structure of $MgTiO_3$ phase were coexisted in all specimens. In the case of SnO addition, the bulk density and dielectric constant were increased but quality factor was decreased with amount of SnO additions. The TCRF of the $0.6TiTe_3O_8-0.4MgTiO_3$+xwt%SnO ceramics were shifted to negative direction. The dielectric constant, quality factor and TCRF of the $0.6TiTe_3O_8-0.4MgTiO_3$ ceramics with 2.5wt% addition of SnO sintered at $830^{\circ}C$ for 1hr were 29.86, 35,800 GHz, -0.58 ppm/$^{\circ}C$, respectively.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1995년도 추계학술발표회 초록집
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• pp.71-74
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• 1995

티타니아계의 흡착제로 최근 주목을 끄는 것은 티탄산칼륨 신소재를 들을 수 있다. 모서리의 chains sharing들과 b축을 따라서 TiO$_{6}$, 즉 8면체의 coner 결합으로 특징 지워지는 티탄산칼륨은 $K_2$O.nTiO$_2$로 표시되는 화합물로 플라스틱의 보강재나 단열재료 용도로 사용되었다. 공업재료로서 중요한 것은 n의 값이 2, 4, 6으로 각각 2티탄산칼륨(K$_2$Ti$_2$O$_{5}$), 4티탄산칼륨(K$_2$Ti$_4$O$_{9}$), 6티탄산칼륨(K$_2$Ti$_{6}$O$_{13}$)으로 불린다. 티탄산칼륨은 기계적 강도가 고강도재료 지르코이나에 해당하고 선팽창계수는 알루미나보다 작아 우수한 내열 및 단열 고강도재료이며 융막재, 이온교환재등으로 쓰인다. 층상구조의 티탄산칼륨을 산처리하여 칼륨을 추출하고 수소이온으로 치환한 결정질 티탄산칼륨 섬유(H$_2$Ti$_4$O$_{9}$.1.2~1.3$H_2O$)는 (H$^{-}$. H$_3$O$^{+}$)Ti$_4$O$_{9}$의 형태를 지니게 된다.

• 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.

• 한국진공학회지
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• 제11권4호
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• pp.240-248
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• 2002

결정성이 좋을 것으로 기대되는 Fe이 도핑된 $Fe_{x}Ti_{l-x}O_2$박막 (x=0.07과 0.16)을 rutile $TiO_2$(110) 기판위에 산소 플라즈마 적층 성장 방법으로 성장시켰다. 도핑되는 Fe의 함량에 따른 표면 특성을 규명하기 위하여 박막 성장은 같은 조건에서 이루어졌다. 여러 가지의 표면분석법을 이용하여 성장된 박막의 표면 특성을 규명하였다. $Fe_{x}Ti_{l-x}O_2$박막에 존재하는 Ti의 산화상태는 +4 이었고 Fe의 경우는 +2와 +3의 산화상태가 섞여있었으며 Fe의 함량이 높은 $Fe_{0.16}Ti_{0.84}O_2$박막에서 $Fe^{3+}$ 이온의 함량이 더 높은 것으로 나타났다. $Fe_{0.07}Ti_{0.93}O_2$박막은 기판과 유사한 평탄한 표면에 막대형과 원통형의 높은 island 형태로 성장되었다. $Fe_{0.16}Ti_{0.84}O_2$박막은 $Fe_{0.07}Ti_{0.93}O_2$ 박막보다는 평탄하지만 적은 island들이 뭉쳐있는 다소 거칠은 표면을 한 다결정성 형태로 성장되어 Fe의 함량에 따라 morphology가 다르게 나타났다.

• 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.

• 한국재료학회지
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• 제1권4호
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• pp.206-213
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• 1991

PbO 77-80wt%, ZnO 4.5-6wt%, $B_2O_3$ 7.5-8.5wt%, $TiO_2$ 3-7wt%, $P_2O_5$ 0.5-2wt%의 조성을 갖는 IC Package봉착용 저융점($400-460^{\circ}C$) 결정화유리 frit를 제조하였다. DTA-TMA, X-선 회절분석, SEM 등을 이용하여 봉착용 유리의 결정화 특성을 연구하였다. $TiO_2$ 함량이 3wt% 함유시료는 $420-440^{\circ}C$에서 $2PbO{\cdot}ZnO{\cdot}B_2O_3$의 결정이 균일성장하였다. $TiO_2$ 함량이 4wt% 첨가된 시료는 $420-440^{\circ}C$에서 $2PbO{\cdot}ZnO{\cdot}B_2O_3와\;PbTiO_3$ 결정이 섞여서 혼합결정을 이루고 있었다. 또한 $TiO_2$ 5wt% 첨가된 시료는 $440-460^{\circ}C$에서 perovskite $PbTiO_3$ 결정만 석출되었다.

• 한국세라믹학회지
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• 제28권3호
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• pp.215-224
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• 1991

The synthesis of SrTiO3 powders having high purity and homogeneous submicron particle size was attempted by the oxalate method. The microstructure and dielectric properties of SrTiO3 based boundary layer capacitor (BLC) were investigated. Strontium titanyl oxalate[SrTiO(C2O4)2.4H2O] was prepared from the mixing solution of (Sr, Ti) using oxalic acid(H2C2O4) as a precipitating agent at 8$0^{\circ}C$. The crystalline SrTiO3 powder was obtained by thermal decomposition of the precipitate above $600^{\circ}C$. The crystalline SrTiO3 powder containing Nb2O5 as a dopant, TiO2 and SiO2 as additives was sintered at 1360~144$0^{\circ}C$ in the reducing atmosphere to get semiconductive SrTiO3. Insulating material containing PbO-Bi2O3-B2O3 frit was printed on the sintered semiconductive SrTiO3 and fired at 120$0^{\circ}C$ for 2h to get the grain boundary diffusion.

• 한국결정성장학회지
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• 제12권2호
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• pp.91-95
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• 2002

Titannium tetra-isoporpoxide의 가수분해 반응을 이용하여 nanosize의 $TiO_2$powder를 합성하고, 가수분해 반응에 있어서 촉매로 사용되는 HCI과 $NH_4$OH의 첨가량에 따른 반응양상과 생성된 $TiO_2$분말의 특성의 변화를 조사하였다. 염기성 촉매인 $NH_4$OH,를 사용하였을 경우에 균질한 형상의 powder 형태의 $TiO_2$를 합성할 수 있었으며, 산성 촉매인 HCI을 사 용하여 p보가 5.04 이하일 경우에는 괴상이나 과립의 형태로 생성되었다. 사용한 촉매의 종류와 양에 따라 저온의 결정상인 anatase의 생성속도와 보다 안정한 rutile상으로의 상전이 속도가 영향을 받았다.

• 한국세라믹학회지
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• 제20권1호
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• pp.43-48
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• 1983

The formation of strontium titanate from several molar $SrCO_3$ and $TiO_2$ mixtures was studied in air and $CO_2$ gas Mixtures of $SrCO_3$ and $TiO_2$ were heated in air at 400-$600^{\circ}C$ DTA-TG was used to obtain thermal histories of simples heated in air and $CO_2$ gas. X-ray diffraction analysis was used to determine both the phase composition and the amounts of each phase present. The phase relationship of various compounds $SrTiO_3$, $Sr_2TiO_4$, $Sr_2Ti_3O_7$ and $Sr_4Ti_3O_{10}$ formed by the sintering in each composition was shown by the calibration curves. High temperature X-ray analysis was used to determine both the formation process and deformation process of each products. Small amount of SrTiO3 is formed first at the surface af contact SrTiO3 reacts with $SrCO_3$ to form Sr2TiO4 this is affected on the $CO_2$ pressure.