• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.102.2-102.2
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• 2012

Different layers of zirconium nitride (ZrN) and hydroxyapatite (HA) coatings were prepared on cp Ti substrate for biomedical applications. The main idea is to improve the mechanical strength as well as the biocompatibility of the coating. ZrN is known for its high mechanical strength, corrosion resistance. HA is well known for its biocompatibility properties. Hence, in this study, both materials were coated on a cp Ti substrate with bottom layer with ZrN for good bonding with substrate and the top layer with HA for induce bioactivity. Middle layer was formed by a composite of HA and ZrN. Detail analyses of the layered coatings for its structural, morphological, topographical properties were carried out. Then the mechanical property of the layered coatings was analyzed by nanoindentation. Biomimetic growths of apatite on the functionally graded coatings were determined by simulated body fluid method. This study provides promising results to use this kind of coatings in biomedical field.

• The Korean Journal of Ceramics
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• 제6권4호
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• pp.333-338
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• 2000

$Ba_{0.7}Sr_{0.3}TiO_3$(BST) thin films were deposited simultaneously on various electrodes and buffers by the sputtering technique. When the substrate temperature was varied, the BST thin film on each electrode showed good crystallinity above $550^{\circ}C$ as revealed by X-ray diffraction measurements. The surface morphology, determined by atomic force microscopy, indicated that the roughness of BST thin films on $RuO_2$was substrate dependent. However, BST thin films on Ru electrodes are smoother and showed no substrate dependence, probably because the precursor surface diffusion length was greater than the sinusoidal perturbations of the wavelength.

• 열처리공학회지
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• 제13권5호
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• pp.324-329
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• 2000

Microstructure, mechanical and fatigue behaviors of TiCN and TiN/TiCN thin films, deposited on quenched and tempered STD61 tool steel, were investigated by using XRD, XPS, hardness, adhesion and fatigue tests. The TiCN thin film is grown along the (100), (111) orientation, whereas the TiN/TiCN thin film is grown along the (111) orientation. The preferred orientation of TiN/TiCN thin film strongly depends on the TiN buffer layer whose orientation is (111), as is well-known. The TiN/TiCN thin film showed the higher adhesion compared with TiCN single layer because the TiN buffer layer, having good toughness, reduces the effects of the lower hardness of substrate. In the high cycle tension-tension fatigue test, the fatigue life of the TiCN and the TiN/TiCN coated steel increased approximately two to four times and five to nine times respectively compared with uncoated specimens. The TiN buffer layer in multilayer thin films plays an important role in reducing residual stress and fatigue crack initiation, and then in restraining the fatigue propagation.

• 한국진공학회지
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• 제1권1호
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• pp.67-72
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• 1992

고에너지 반사 전자회절기(RHEED) 및 투과전자현미경(HRTEM)을 이용하여 Si(111)-7 $\times$ 7 면에서의 Ti 박막의 성장 mode와 Si(111) 면에서의 C54 TiSi2의 정합성장 을 조사하였다. 초고진공에서 Si(111)-7 $\times$ 7 표면에 상온에서 Ti를 증착하면 Ti/Si 계면에 서 비정질의 Ti-Si 중간막이 먼저 형성되고 그 위에 Ti 박막은 다결정으로 성장하였다. 160ML의 Ti를 증착한 시료를 초고진공 내에서 75$0^{\circ}C$로 10분 열처리하면 C54 TiSi2가 정합 성장하였으며 이는 HRTEM 격자상 및 TED Pattern으로 확인할 수 있었다. TiSi2/Si(111) 시 료를 다시 $900^{\circ}C$로 가열하면 TiSi2위에 단결정 Si층이 [111] 방향으로 성장하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
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• pp.194-196
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• 2004

$BaTiO_3/SrTiO_3$ heterolayered thick films on the $Al_2O_3$ substrate by screen printing method with stacking periodicity. The stacking periodicity of $BaTiO_3/SrTiO_3$ heterolayer structure was varied from $(BaTi_O_3)_1/(SrTiO_3)_1$ to $(BaTi_O_3)_3/(SrTiO_3)_3$. The total thickness of the $BaTiO_3/SrTiO_3$ films was about $120{\mu}m$. There was an interdiffusion at the interface of the $BaTiO_3$ and $SrTiO_3$ layers. The dielectric constant of $BaTiO_3/SrTiO_3$ heterolayered thick films was increased with decreasing stacking periodicity of the $BaTiO_3/SrTiO_3$. The dielectric constant of the ($(BaTi_O_3)_1/(SrTiO_3)_1$ herterolayered thick films was about 1780.

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2660-2664
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• 2014

A simple method of depositing titanium dioxide ($TiO_2$) nanoparticles onto graphene oxide (GO) as a catalytic support was devised for photocatalytic degradation of methylene blue (MB). Thiol groups were utilized as linkers to secure the $TiO_2$ nanoparticles. The resultant GO-supported $TiO_2$ (GO-$TiO_2$) sample was characterized by transmission electron microscopy (TEM), near-edge X-ray absorption fine structure (NEXAFS), and X-ray photoelectron spectroscopy (XPS) measurements, revealing that the anatase $TiO_2$ nanoparticles had effectively anchored to the GO surface. In the photodegradation of MB, GO-$TiO_2$ exhibited remarkably enhanced photocatalytic efficiency compared with thiolated GO and pure $TiO_2$ nanoparticles. Moreover, after five-cycle photodegradation experiment, no obvious deactivation was observed. The overall results showed that thiolated GO provides a good support substrate and, thereby, enhances the photodegradation effectiveness of the composite photocatalyst.

• 한국세라믹학회지
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• 제30권4호
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• pp.332-338
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• 1993

TiN/Ti is the best buffer layer between PZT thin film and si substrate among the Ti, TiN, ZrN, TiN/Ti, ZrN/Ti. The amorphous PZT films deposited on TiN/Ti buffer layer directly transform into perovskite phase when rapid thermal annealed for 30sec above 55$0^{\circ}C$. As Rapid Thermal Annealing(RTA) temperature increased, the remanent polarization(Pr) and dielectric constant($\varepsilon$r) increased and then showed Pr=21 $\varepsilon$r=593 when rapid thermal annealed 80$0^{\circ}C$ for 30sec. On the contrary the leakage current increased with increasing RTA temperature due to the formation of void made by Pb evaporationand grain cohesion.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.269-270
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• 2006

이온빔 스퍼터를 사용하여 PC기판위에 $TiO_2$ 박막을 증착한 후 광학적 특성을 고찰하였다. 증착 전 어시스트 이온건을 사용하여 아르곤 플라즈마로 표면처리를 하였으며, Ti 박막을 $300{\AA}$정도로 증착한 다음, 그 위에 산소 반응스퍼터링 기법을 사용함으로써 $TiO_2$박막을 증착하였다. 표면처리에 의한 기판의 표면개질로 TI 버퍼층과의 막부착력을 높이고, 아르곤 산소의 분압비를 1로 고정하였을 때, $TiO_2$박막의 두께에 따라서 박막의 색상이 변화는 것을 관찰할 수 있었다. 또한, 아르곤과 산소의 분압 변화에 대한 의존성은 $TiO_2$박막의 색상과 투과율과 같은 광학적인 성질에 영향을 미치는 것을 알 수 있었다.

• E2M - 전기 전자와 첨단 소재
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• 제5권4호
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• pp.406-410
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• 1992

본 논문에서는 MgFe$_{2}$O$_{4}$ 세라믹스의 구조적 특성을 개선하기 위하여 TiO$_{2}$를 0-10[wt%] 첨가하여 세라믹스를 만들고 TiO$_{2}$가 습도센서용 MgFe$_{2}$O$_{4}$ 세라믹스의 구조적 특성에 미치는 영향을 조사하였다. 각 시편은 TiO$_{2}$가 첨가되는 양이 증대함에 따라 NgTi$_{2}$O$_{5}$의 이상이 나타났다. TiO$_{2}$의 첨가량이 6[wt%]일 때 까지는 시편의 밀도가 증가하여 기공율의 저하를 가져왔고 기공의 크기가 최소가 되는 조성은 5[wt%]의 TiO$_{2}$가 첨가되었을 때이며 이때의 평균 기공의 크기는 1615[.angs.]이었다. 따라서 5[wt%]의 TiO$_{2}$를 첨가했을 때가 기공의 크기 조절에 최적이라고 생각되며 센서용 기판으로 응용하기 적합하다고 생각된다.

• 한국세라믹학회지
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• 제31권12호
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• pp.1577-1587
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• 1994

TiO2 thin films with the substitution of oxygen with nitrogen were deposited on silicon substrate by metalorganic chemical vapor deposition (MOCVD) using Ti(OCH(CH3)2)4 (titanium tetraisopropoxide, TTIP) and N2O as source materials. X-ray diffraction (XRD) results indicated that the crystal structure of the deposited thin films was anatase TiO2 with only (101) plane observed at the deposition temperatures of 36$0^{\circ}C$ and 38$0^{\circ}C$, and with (101) and (200) plane at above 40$0^{\circ}C$. Raman spectroscopic results indicated that the crystal structure was anatase TiO2 in accordance with the XRD results without any rutile, fcc TiN, or hcp TiN structure. No fundamental difference was observed with temperature increase, but the peak intensity at 194.5 cm-1 increased with strong intensity at 143.0 cm-1 for all samples. The crystalline size of the films varied from 49.2 nm to 63.9 nm with increasing temperature as determined by slow-scan XRD experiments. The refractive index of the films increased from 2.40 to 2.55 as temperature increased. X-ray photoelectron spectroscopy (XPS) study showed only Ti 2s, Ti 2p, C 1s, O 1s and O 2s peaks at the surface of the film. The composition of the surface was estimated to be TiO1.98 from the quatitative analysis. In the bulk of the film Ti 2s, Ti 2p, O 1s, O 2s, N 1s and N 2s were detected, and Ti-N bonding was observed due to the substitution of oxygen with nitrogen. A satellite structure was observed in the Ti 2p due to the Ti-N bonding, and the composition of titanium nitride was determined to be about TiN1.0 from the position of the binding energy of Ti-N 2p3/2 and the quatitative analysis. The spectrum of Ti 2p energy level could be the sum of a 4, 5, or 6 Gaussian curve reconstruction, and the case of the sum of the 6 Gaussian curve reconstruction was physically most meaningful. From the results of Auger electron spectroscopy (AES), it was known that the composition was not varied significantly throughout the whole thickness of the film, and silicon oxide was not observed at the interface between the film and the substrate. The composition of the film was possible (TiO2)1-x.(TiN)x or TiO2-2xNx and in this experimental condition x was found to be about 0.21-0.16.