• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.9
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• pp.459-463
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• 2004

In this study, the (l-x)$TiTe_3O_{8}$-x$MgTiO_3$ ceramics were investigated to obtain the improved dielectric properties of a high temperature stability and a sintering temperature of less than $900^{\circ}C$ which was necessary for the LTCC. According to the X-ray diffraction patterns of the (l-x)$TiTe_3O_{8}$-x$MgTiO_3$(x=0∼1) ceramics, the columbite structure of $TiTe_3O_{8}$ and ilmenite structure of $MgTiO_3$ were coexisted. Increasing the $MgTiO_3$ mole ratio(x), the density and dielectric constant were decreased and temperature coefficient of resonant frequency was moved to the negative direction and the quality factor was increased. In the case of the 0.6$TiTe_3O_{8}$-0.4$MgTiO_3$ ceramics sintered at $830^{\circ}C$ for 3hr., the microwave dielectric properties were $\varepsilon_{\gamma}$=29.3, Q${\times}$$f_{\gamma}$=39.600GHz and $\tau$$_{f}$=+9.3ppm/$^{\circ}C$.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.4
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• pp.509-516
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• 2020

An important property of glass and ceramic solid waste forms is processability. Tellurite materials with low melting temperatures and high halite solubilities have potential as solid waste forms. Crystalline TiTe3O8 was synthesized through a solid-state reaction between stoichiometric amounts of TiO2 and TeO2 powder. The resultant TiTe3O8 crystal had a three-dimensional (3D) structure consisting of TiO6 octahedra and asymmetric TeO4 seesaw moiety groups. The melting temperature of the TiTe3O8 powder was 820℃, and the constituent TeO2 began to evaporate selectively from TiTe3O8 above around 840℃. The leaching rate, as determined using the modified American Society of Testing and Materials static leach test method, of Ti in the TiTe3O8 crystal was less than the order of 10-4 g·m-2·d-1 at 90℃ for durations of 14 d over a pH range of 2-12. The chemical durability of the TiTe3O8 crystal, even under highly acidic and alkaline conditions, was comparable to that of other well-known Ti-based solid waste forms.

• Proceedings of the KIEE Conference
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• 2008.10a
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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.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1299-1300
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• 2007

In this study, low temperature sintering property of (1-x)$TiTe_{3}O_{8}-xMgTiO_{3}$ ceramics were investigated for LTCC application which enable to cofiring with Ag electrode. $TiTe_{3}O_{8}$ mixed with $MgTiO_3$ to improve the temperature property. In the X-ray diffraction patterns, the columbite structure of $TiTe_{3}O_{8}$ phase and ilmenite structure of $MgTiO_3$ phase were coexisted in all specimens. The bulk densities and dielectric constants were decreased with increasing of $MgTiO_3$. However, the quality factors were increased with $MgTiO_3$ addition. Also, TCRF was shifted to negative(-) direction. Microwave dielectric properties of (1-x)$TiTe_{3}O_{8}-xMgTiO_{3}$ ceramics had similar tendency with calculated value by the mixing rule. The dielectric constant, quality factor and TCRF of $05TiTe_{3}O_{8}-0.5MgTiO_{3}$ ceramics sintered at $830^{\circ}C$ for 3h. were 26.19, 43,290GHz and $-3.9ppm/^{\circ}C$, respectively.

• Proceedings of the KIEE Conference
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• 2007.11a
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• pp.114-115
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• 2007

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 $TiTe_3O_3$ phase and ilmenite structure of $MgTiO_3$ phase were coexisted in all specimens. In the case of $H_3BO_3$ addition, the bulk density and dielectric constant were decreased but quality factor was increased with amount of $H_3BO_3$ additions. The TCRF of the $0.6TiTe_3O_8-0.4MgTiO_3+xwt%H_3BO_3$ ceramics were moved to positive direction. In another case, SnO addition, the bulk density and dielectric constant were increased but Quality factor was decreased with amount of SnO additions. The TCRF of the $0.6TiTe_3O_8-0.4MgTiO_3$+ywt%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 $2wt%H_3BO_3$ and 2.5wt%SnO sintered at $830^{\circ}C$ for 1h, were 28.5, 39,570GHz, $+9.34ppm/^{\circ}C$ and 29.86, 35,80000z, $-0.58ppm/^{\circ}C$, respectively.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1589-1591
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• 2003

The microwave dielectric properties of $TiTe_3O_8-CaF_2$ ceramics were investigated. All sample of $TiTe_3O_8-CaF_2$ ceramics were prepared by the conventional mixed oxide method, and sintered in the temperature of $730^{\circ}C{\sim}750^{\circ}C$. The structural properties of $TiTe_3O_8-CaF_2$ ceramics were investigated by the X-ray diffractor meter. According to the X-ray diffraction patterns of $TiTe_3O_8-CaF_2$ ceramics, the major phase of the cubic $TiTe_3O_8$ were presented. In the case of $1molTiTe_3O_8-0.1molCaF_2$ ceramics sintered at $740^{\circ}C$ for 5hr., the bulk density, dielectric constant, quality factor were $2.8g/cm^3$, 39.1, 36.100GHz, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.342-343
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• 2005

In this study,. the microwave dielectric properties of the $0.6TiTe_3O_8-0.4CaWO_4$ ceramics with sintering temperature were investigated for LTCC application. According to the X-ray diffraction patterns, the $0.6TiTe_3O_8-0.4CaWO_4$ ceramics had columbite structure of the $TiTe_3O_8$ phase and scheelite structure of the $CaWO_4$ phase. Increasing the sintering temperature, the bulk density, the dielectric constant and the quality factor of the $0.6TiTe_3O_8-0.4CaWO_4$ ceramics were increased. In the case of the $0.6TiTe_3O_8-0.4CaWO_4$ ceramics sintered at $810^{\circ}C$, the bulk density, the dielectric constant and the quality factor were 5.72$g/cm^2$, 33.6, 22,013GHz respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.1
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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.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.4
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• pp.144-148
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• 2005

In this study, the microwave dielectric properties of $0-6TiTe_3O_8-0.4MgTiO_3$ ceramic with $H_3BO_3$ and SnO were investigated to reduce the sintering time for the LTCC application. According to the X-ray diffraction patterns, both of $0-6TiTe_3O_8-0.4MgTiO_3$ ceramic with $H_3BO_3$ and SnO had the columbite structure of $TiTe_3O_8$ Phase, the ilmenite structure of $MgTiO_3$ phase. The density and dielectric constant of the $0-6TiTe_3O_8-0.4MgTiO_3$ ceramics with $H_3BO_3$ sintered at $830^{\circ}C$ for 1 hour were decreased but the quality factor was not changed with addition of $H_3BO_3$. Also the temperature coefficient of resonant frequency was not changed hardly. In the case of addition of SnO, the density and dielectric constant were increased but the quality factor was decreased and the temperature coefficient of resonant frequency was shifted to the negative(-) direction.

• Journal of Sensor Science and Technology
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• v.2 no.1
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• pp.101-108
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• 1993

$TiO_{2}$/Se : Te heterojunction for color sensor has been fabricated by RF reactive sputtering and thermal evaporation methods onto glass substrate. The optimum deposition condition of $TiO_{2}$ films was such that RF power was 120 W, substrate temperature was $100^{\circ}C$, oxygen concentration was 50%, working pressure was 50 mTorr for the $TiO_{2}$ film thickness of $1000{\AA}$. In this case, the optical transmittance of $TiO_{2}$ film at 550 nm-wavelength was 85%, resistivity was $2{\times}10^9{\Omega}{\cdot}cm$, refractive index was 2.3, and optical bandgap was 3.58 eV. The composition ratio of 0 to Ti by AES analysis was 1.7. When $TiO_{2}$ films were annealed at $400^{\circ}C$ for 30 min. in $O_{2}$ ambient, the optical transmittance of $TiO_{2}$ films at the wavelength range of $300{\sim}580$ nm was improved from 0 to 25%. When Se : Te films were annealed at $190^{\circ}C$ for 1 min., photosensitivity under illumination of 1000 lux was 0.75. The optical bandgap of Se : Te films was 1.7 eV. The structures of Se : Te films were the hexagonal with (100) and (110) orientation. The spectral response of a-Se was improved by the addition of Te, especially in the long wavelength region. The $TiO_{2}$/Se : Te heterojunction showed wide spectral response, and more improved one than that of a-Si film in the blue light region.