• Applied Chemistry for Engineering
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• v.9 no.4
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• pp.585-590
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• 1998

Fibrous $Na_xTi_nO_{2n+1}$ whisker was prepared by $H^+/Na^+$ ion-exchange on layered hydrous titanium dioxide ($H_2Ti_4O_9{\cdot}nH_2O$). The ion-exchange reaction was proceeded at 0.5~2.0 M NaOH solution. In the ion-exchange at 2.0 M NaOH solution, 73% of sodium was exchanged and the prepared $Na_xTi_nO_{2n+1}$ whisker was a fibrous crystal of about $10{\sim}20{\mu}m$ of length and about $0.7{\mu}m$ of diameter. The phase transition of the ion-exchange phases identified by the thermal analysis. The result showed that the $Na_xTi_nO_{2n+1}$ whisker was decomposed into $Na_2Ti_6O_{13}$ and $TiO_2$ in the temperature of $200{\sim}600^{\circ}C$.

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.30.2-30
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• 2002

• ETRI Journal
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• v.31 no.6
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• pp.675-679
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• 2009

$Ti_xSi_{1-x}O_y$ (TSO) thin films are fabricated using plasma-enhanced atomic layer deposition. The Ti content in the TSO films is controlled by adjusting the sub-cycle ratio of $TiO_2$ and $SiO_2$. The refractive indices of $SiO_2$ and $TiO_2$ are 1.4 and 2.4, respectively. Hence, tailoring of the refractivity indices from 1.4 to 2.4 is feasible. The controllability of the refractive index and film thickness enables application of an antireflection coating layer to TSO films for use as a thin film solar cell. The TSO coating layer on an Si wafer dramatically reduces reflectivity compared to a bare Si wafer. In the measurement of the current-voltage characteristics, a nonlinear coefficient of 13.6 is obtained in the TSO films.

• Journal of the Korean Ceramic Society
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• v.31 no.12
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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.

• Journal of the Korean Ceramic Society
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• v.13 no.2
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• pp.24-30
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• 1976

To observe the influence of tetrahedral and octahedral preference of cations of Ni2+, Ti4+ upon the formation and the color development of the MgO-SnO2 spinel containing Ni2+ and Ti4+ ions, the gradual substitution of Ni2+ ions for Mg2+ ions and of Ti4+ ions for Sn4+ ions of the spinel in NiO-MgO-SnO2-TiO2 system was carried out. On samples prepared by calcining the oxide and basic carbonate mixtures at 130$0^{\circ}C$ for 1.5 hour, the X-ray analysis, measurement of reflectance and the test of their stability as a glaze pigment were also carried out. On samples prepared by calcining the oxide and basic carbonate mixtures at 130$0^{\circ}C$ for 1.5 hour, the X-ray analysis, measurement of reflectance and the test of their stabiality as a glaze pigment were also carried out. The results are summarized as follows. 1) As increasing the amounts of Ni2+ ions in the xNiO.(2-x)MgO.SnO2 system, spinel was not formed easily, and the mixed-spinel was formed in NiO.MgO.SnO2 of x=1 but the spinels was not formed completely in the range of x>1.5 2) The spinels was not more formed in NiO-MgO-TiO2 system than NiO-MgO-SnO2 system. Therefore, Ti4+ ions have strong octahedral preference than Sn4+ ions. The color changed the yellow region little. The mixed-spinel or non-spinel was formed easily NiO.TiO2, MgO.TiO2 of illmenite type as the gradual substitution of Ti4+ ions for Sn4+ ions. 3) The results of glaze test. The color changed from white through graish brown to brown as the gradual substitution of Ni2+ ions for Mg2+ ions in calcium-zinc glaze and calcium glaze, and from white through light yellowish beige to dull beige in tile glaze. Also, the color did not change generally as the gradual substitution of Ti4+ ions for Sn4+ ions in NiO-MgO-SnO2-TiO2 system.

• Journal of the Korean Ceramic Society
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• v.33 no.12
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• pp.1311-1318
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• 1996

• Journal of the Microelectronics and Packaging Society
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• v.6 no.2
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• pp.75-81
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• 1999

$CaTiO_3$-$ La(Mg_{2/3}Ta_{1/3})O_3$ solid solutions were prepared in order to improve the microwave dielectric properties of $CaTiO_3$. XRD analysis revealed that the crystal structure of the solid solution changed from orthorhombic to monoclinic as the amount of $ La(Mg_{2/3}Ta_{1/3})O_3$increased. When x=0.3 in (1-x)$CaTiO_3+xLa(Mg_{2/3}Ta_{1/3})O_3$, the dielectric constant was 49, the temperature coefficient of resonance frequency was +$14ppm/^{\circ}C$, and $Q \times f_0$ was 17000.

• Journal of the Korean Electrochemical Society
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• v.14 no.1
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• pp.16-21
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• 2011

$Li_4Sn_xTi_{5-x}O_{12}$ was manufactured by high energy ball milling (HEBM) and used as an anode material for lithium ion battery. Various amount of $SnO_2$was added to $Li_4Ti_5O_{12}$ and heated at different temperatures. The purpose of this research was to see the effect of $SnO_2$ addition into $Li_4Ti_5O_{12}$. Manufactured samples were analyzed by TGA, XRD, SEM, PSA. Battery cycler was used to test the charge/discharge properties of active materials. Heat treatment temperature of $800^{\circ}C$ was needed to make a stable structure of $Li_4Sn_xTi_{5-x}O_{12}$ and the particle size distribution was $0.2{\sim}0.6\;{\mu}m$. Charge/discharge process was repeated for 50 cycles at room temperature. The initial capacity was 168mAh/g and the voltage plateau was observed at 1.55V(Li/$Li^+$).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04a
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• pp.148-151
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• 2000

$Mg_{2-2x}Ti_xO_2$ films were prepared by e-beam evaporation method to be used as possible substitutes for the conventional MgO protective layer. The oxygen content in the films and in turn, the ratio of metal to oxygen gradually increased with increasing the $TiO_2$ content in the starting materials. The pure MgO films exhibited the crystallinity with strong (111) orientation. The $Mg_{2-2x}Ti_xO_2$ films, however, had the crystallinity with (311) preferred orientation. When the $[TiO_2/(MgO+TiO_2)]$ ratios of 0.1 and 0.15 were used, the deposited films exhibited the secondary electron emission yields improved by 50% compared to that of the conventional MgO protective layer, which resulted in reduction in discharge voltage by 12%.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1309-1311
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• 1998

$Pb_{1-x}La_xTi_{1-x/4}O_3$ (PLT(x)) thin film has been regarded as one of the most promising materials for applications of sensor, optic devices, and memory devices, because it exhibits various properties as changing the amount of Lanthanum component. So we have prepared PLT thin films on platinized silicon (actually Pt/Ti/$SiO_2$/Si) substrates in oxygen ambient by laser ablation. Energy dispersive X-ray (EDX) revealed that the stoichiometric thin films were fabricated.