• 한국세라믹학회지
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• 제37권10호
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• pp.938-943
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• 2000

TiCl$_4$, 물 및 1-propanol의 혼합용액으로부터 미립 TiO$_2$분말 제조시, 1-propanol과 물의 부피비, 반응온도, 반응유지시간 및 TiCl$_4$mole 농도에 따른 분말 특성 및 결정상 생성에 대해 조사하였다. 반응온도가 3$0^{\circ}C$ 이상일 때 Ti 수화물의 초기 침전이 생성되었고 반응온도가 TiCl$_4$mole 농도가 증가함에 따라 입자크기는 증가하였고 $600^{\circ}C$ 하소시 1-propanol과 물의 부피비가 2보다 크고 반응온도가 7$0^{\circ}C$보다 낮을 때 주결정상은 anatase였다. 입자크기가 미세하고 입자크기 분포가 좁은 범위를 갖는 조건은 1-propanol과 물의 부피비가 2, 반응온도가 7$0^{\circ}C$, TiCl$_4$mole 농도가 0.2 mole/ι일 때였으며, 결정상의 생성은 1-propanol과 물의 부피비가 2, 반응온도가 3$0^{\circ}C$ 이상일 때 anatase에서 rutile로 전이하는 온도가 높아졌다. 이와 같은 반응인자에 따른 효과는 용매의 유전상수, 티타니아의 용해도, 입자의 표면전위 등의 효과와 관계가 있었다.

• 공업화학
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• 제4권1호
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• pp.64-74
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• 1993

국내 부존 함티탄자철광으로부터 염화티타늄($TiCl_4$)을 제조키 위해 함티탄자철광의 arc-smelting으로부터 얻어지는 titanium slag의 유동층 염소화 반응을 조사하였다. Titanium slag의 유동층 염소화반응에 적절한 반응조건은 반응 온도 $950^{\circ}C$, 반응시간 90분, 염소가스의 유속 3.0cm/sec, titanium slag에 대한 petroleum coke의 무게비 0.18, 그리고 titanium slag 및 petroleum coke의 입자의 평균직경은 각각 $44.6{\mu}m$, $67.9{\mu}m$였다. 위 조건하에서 titanium slug 중의 97.07%의 티타늄이 염소화 되었으며 제조된 염화티타늄($TiCl_4$)의 순도는 96.2%였다.

• 한국분말재료학회지
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• 제11권4호
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• pp.322-327
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• 2004

Ultrafine titanium carbide particles were synthesized by the reaction of liquid-magnesium and vaporized TiCl$_{4}$+C$_{x}$Cl$_{4}$(x = 1 and 2) solution. Fine titanium carbide particles with about 50 nm were successfully produced by combining Ti and C atoms released by chloride reduction of magnesium, and vacuum was then used to remove the residual phases of MgCl$_{2}$ and excess Mg. Small amounts of impurities such as O, Fe, Mg and Cl were detected in the product, but such problem can be solved by more precise process control. The lattice parameter of the product was 0.43267 nm, near the standard value. With respect to the reaction kinetics, the activation energy for the reactions of TiCl$_{4}$+C$_{2}$Cl$_{4}$and Mg was found to 69 kJ/mole, which was about half value against the use of TiCl$_{4}$+CCl$_{4}$, and such higher reactivity of the former contributed to increase the stoichiometry until the level of TiC$_{0.96}$ and decrease the free carbon content below 0.3 wt.%.

• Bulletin of the Korean Chemical Society
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• 제20권8호
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• pp.893-896
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• 1999

Novel citric acid based Ti, Nb and Ta precursors that are highly stable in the presence of water were developed. No alkoxides of Ti, Nb and Ta were utilized in the preparation, instead much less moisture-sensitive metallic Ti, NbCl5 and TaCl5 were chosen as starting chemicals for Ti, Nb and Ta, respectively. The feasibility of these chemicals as precursors is demonstrated in the powder synthesis of BaTi4O9, Y3NbO7 and LiTaO3. The water-resistant Ti precursor was employed as a new source of water-soluble Ti in the amorphous citrate method, and phase pure BaTi4O9 in powdered form was successfully synthesized at 800 ？. The Pechini-type polymerizable complex method using the water-resistant Nb and Ta precursors was applied to the synthesis of Y3NbO7 and LiTaO3, and both the powder materials in their pure form were successfully synthesized at reduced tempera-tures, viz. 500-700 ？. The remarkable retardation of hydrolysis of these water-resistant precursors is explained in terms of the partial charge model theory.

• 한국광학회지
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• 제5권4호
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• pp.499-504
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• 1994

불꽃가수분해 증착방법으로 $SiCl_{4}$, TMB, $TiCL_{4}$등을 사용하여 Ti doped BSG 실리카 입자박막을 실리콘 기판위에 증착하고 증착된 입자층을 녹여서 집적광학용 박막을 제작하였다. 박막의 증착 속도는 $0.5{\mu}m$분 이상으로서 수십 ${\mu}m$의 후막을 빠르게 증착할 수 있었으며 $TiO_{2}$의 첨가량에 따라 BSG 박막의 굴절률을 0.3% 이상 변화시킬 수 있었다. 그 결과 통신용 광섬유와 크기 및 굴절률 분포가 BSG박막의 굴절률을 0.3% 이상 변화시킬 수 있었다. 그 결과 통신용 광섬유와 크기 및 굴절률 분포가 유사한 광도파로를 제작하였다. 보통 B의 도판트로는 $BCl_{3}$를 쓰나 여기서는 TBM를 사용한 결과 TBM도 B의 도판트로 적합함을 알았다. B의 첨가에 의하여 실리카 입자막의 녹는점을 $1200^{\circ}C$로 낮출 수 있었다. 또한 FTIR에 의한 박막의 조성비분석 결과 BSG박막에 $B_2O_3$ 함량이 최대 10mol%로 나타났다.

• 한국전기전자재료학회논문지
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• 제14권10호
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• pp.785-791
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• 2001

High dielectric (Ba, Sr) TiO$_3$ thin films were etched in an inductively coupled plasma (ICP) as a function of Cl$_2$/Ar mixing ration. Under Cl$_2$(20)/Ar(80), the maximum etch rate of the BST films was 400 $\AA$/mim and selectivities of BST to Pt and PR were obtained 0.4 and 0.2, respectively. Etching products were redeposited on the surface of BST and resulted in varying the nature of crystallinity. Therefore, we investigated the etched surface of BST by x-ray photoelectron spectroscopy (XPS) atomic force microscopy (AFM) and x-ray diffraction (XRD). From the result of XPS analysis, we found that residues of Ba-Cl and Ti-Cl bonds remained on the surface of the etched BST for high boiling point. The morphology of the etched surfact was analyzed by AFM. A smoothsurface(roughness ~2.8nm) ws observed under Cl$_2$(20)/Ar(80), rf power of 600 W, dc bias voltage of -250 V and pressure of 10 mTorr. This changed the nature of the crystallinity of BST. From the result of XRD analysis, the crystallinities of the etched BST film under Ar only and Cl$_2$(20)/Ar(80) were maintained as similar to as-deposited BST. However, intensity of BST(100) orientation under Cl$_2$ only plasma was abruptly decreased. This indicated that CI compounds were redeposited on the etched BST surface and resulted in changed of the crystallinity of BST during the etch process.

• 한국전기전자재료학회논문지
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• 제25권9호
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• pp.681-685
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• 2012

We investigated the dry etching characteristics of TiN in $TiN/Al_2O_3$ gate stack using a inductively coupled plasma system. TiN thin film is etched by BCl3/He plasma. The etching parameters are the gas mixing ratio, the RF power, the DC-bias voltages and process pressures. The highest etch rate is in $BCl_3/He$ (25%:75%) plasma. The selectivity of TiN thin film to $Al_2O_3$ is pretty similar with $BCl_3/He$ plasma. The chemical reactions of the etched TiN thin films are investigated by X-ray photoelectron spectroscopy. The intensities of the Ti 2p and the N 1s peaks are modified by $BCl_3$ plasma. Intensity and binding energy of Ti and N could be changed due to a chemical reaction on the surface of TiN thin films. Also we investigated that the non-volatile byproducts such as $TiCl_x$ formed by chemical reaction with Cl radicals on the surface of TiN thin films.

• Journal of Advanced Marine Engineering and Technology
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• 제19권3호
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• pp.62-69
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• 1995

In order to investigate the effect of TiN coating on corrosion fatigue behavior of metal, the rotary bending corrosion fatigue tests were carried out in 3% NaCl solution by using the round bar specimens of high-speed steel, SKH-9, coated with TiN by PVD method. From the experimental results, fatigue strength of TiN coating steel in air was obvious improvement as compared with that of the substrate because of the restriction of dislocation movement in near surface of the substrate by hard thin film. In 3% NaCl solution, corrosion fatigue life of TiN coating specimen in high stress level was improvement same as in air. But in low stress level, corrosion fatigue life of TiN coating one was equivalent to that without coating, due to much crack initiated from corrosion pits formed at the substrate by failure of coating layer.

• Korean Chemical Engineering Research
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• 제45권4호
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• pp.410-413
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• 2007

불균일계 중합촉매내 내부전자공여체(ID)의 존재 유무와 종류가 에틸렌과 1-부텐 간의 공중합에서 얻어지는 공중합물에 미치는 영향에 대하여 살펴보았다. 실리카 담지 $TiCl_4$ 촉매를 실리카 담지체에 ethylaluminium dichloride, magnesium alkyl, 2-ethyl-1-hexanol, $TiCl_4$와 여러 종류의 ID 등을 이용하여 제조하였으며 이 때 ID와 Ti의 몰비를 0.5로 고정하였다. ID는 ethylbenzoate(EB), diisobuylphthalate(DIBP), dioctylphthalate(DOP)을 사용하였다. ID가 촉매 내에 존재하는 경우 Ti(+3)의 함량비가 증가하였다. 공중합 활성은 EB를 $TiCl_4$ 반응 후에 투입한 촉매가 가장 높았으며 그 외의 ID가 존재하는 촉매는 활성이 감소하는 현상을 보였다. Xylene soluble(XS) 측정값은 ID가 존재하는 모든 중합촉매가 ID가 없는 경우 보다 50% 이상 감소하였으며 Crystaf 분석 결과 DIBP가 존재하는 촉매가 상대적으로 균일한 화학조성분포를 보였다. 이는 ID가 분균일한 촉매활성점을 보다 균일하게 만드는 역할에서 기인한 것으로 보이며 입체규칙성을 갖는 활성점을 만들거나 비입체규칙성 활성점을 blocking하는 역할 때문인 것으로 설명할 수 있다.

• 한국세라믹학회지
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• 제21권2호
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• pp.165-173
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• 1984

It is desirable to establish reliable synthetic methods for electro-ceramic materials. To synthesize $SrTiO_3$ in this study direct solid state reactions and wet chemical processes were used. Previous study of $SrTiO_3$ synthesis included oxalated-method($SrTiO(C_2O_4)_2$.$4H_2O$) co-precipitation$(SrCO_3+TiO(OH)_2)$ and direct solid state reaction$(SrCO_3+TiO(OH)_2)$ The methods in question lead to intermediate inclusion during the reactions and less controllable in particle sizes of $SrTiO_3$. To obtain highly pure $SrTiO_3$ so-called "direct wet process method" was added in this investigation. In the study the "direct wet process" was for the first time applied to synthesize chemically pure and fine particle $SrTiO_3$. $SrCl_2$ and $TiCl_4$<\ulcornerTEX> at KOH solution at room temperature to 10$0^{\circ}C$ precipitated $SrTiO_3$ The particle size increased as temperature increased.mperature increased.