• Journal of the Korean Ceramic Society
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• v.32 no.12
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• pp.1331-1336
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• 1995

The glass-ceramics for ferro-electric were made from compositions of 70PbO.16TiO2.8SiO2.4B2O3.2AlPO4 (wt%) and 67.5PbO.20TiO2.8.5SiO2.2B2O3.2AlPO4 (wt%). The crystallization kinetics for PbTiO3 crystalline phase formation from glass was studied using non-isothermal DSC techniques. The values of activation energy, ΔE using variables of heating rate and temperature were calculated at various reaction fractions obtained from peak area over DSC. The results indicated that activation energy was lowest at 60% reaction fractions and the activation energy of glass containing 20.0 wt% TiO2 is higher than that of glass containing 16.0 wt% TiO2. The crystallization mechanism was three dimensional growth (n=4).

• Proceedings of the Materials Research Society of Korea Conference
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• 2001.11a
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• pp.186-186
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• 2001

• Proceedings of the Korean Ceranic Society Conference
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• 2000.10a
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• pp.158.2-158
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• 2000

• Proceedings of the Materials Research Society of Korea Conference
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• 2001.11a
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• pp.187-187
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• 2001

• Korean Journal of Materials Research
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• v.11 no.4
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• pp.305-311
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• 2001

$PbO-B_2O_3-SiO_2-Al_2O_3$, system was investigated for optical, thermal and electrical properties of transparent dielectric. We also studied the reaction between transparent dielectric and transparent electrode(Indium Tin Oxide, ITO) during firing. For the evaluation of properties, dielectrics were prepared under the conditions fired at 520~58$0^{\circ}C$ with 12$\mu\textrm{m}$ thickness. In the reaction between dielectrics and electrode(ITO), In ions diffused into dielectric layer, while Sn ion diffusion was not observed. The coefficient of thermal expansion, the dielectric constant, the glass transition temperature and the transmittance of the dielectric were greatly dependent on PbO content. The increase of the coefficient of thermal expansion and the dielectric constant were monitored by increasing PbO, while the glass transition temperature and the transmittance were decreased. With the increased $Al_2O_3/B_2O_3$ ratio, the coefficient of thermal expansion and the transmittance were decreased, while the dielectric constant was increased. The glass transition temperature did not change significantly.

• Korean Journal of Materials Research
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• v.12 no.5
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• pp.347-352
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• 2002

A transparent dielectric of the $PbO-B_2O_3-SiO_2-A1_2O_3$ system which was a low melting glass has been used for PDP (Plasma Display Panel), but it has a problem which is a reaction to be occurred between a transparent dielectric layer and electrodes (Ag, ITO) after firing. This research was conducted for ion migration of $Ag^+\$ and $Sn^ {2+}$ during firing three different frits of low melting glass. The result showed that yellowing phenomena occurred through a chemical reaction between $Ag^+\$and $Sn^ {2+}$ at 550~58$0^{\circ}C$ for 20~60 min. In addition, it was confirmed that the migration of $Sn^{2+}$ from ITO electrode made a strong effect on the yellowing phenomena.

• Journal of the Korean Ceramic Society
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• v.39 no.5
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• pp.438-445
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• 2002

In this study, the glass frit of $PbO-TiO-2-SiO_2-BaO-ZnO-Al_2O-3-CaO-B_2O_3-Bi_2O_3-MgO$ system was manufactured. The glass was melted at $1,400{\circ}C$, quenched and attrition-milled. The glass frit powder was pressed and fired for 2h at the range of $750~1,000{\circ}C$. The crystallization of glass frit began at about $750{\circ}$ and at low temperature, the main crystal phases were hexagonal celsian($BaAl_2Si_2O_8$) and alumina. As the firing temperature increased, the crystal phases of monoclinic celsian, zinc aluminate, zinc silicate, calcium titanium silicate and titania appeared. And the increase of firing temperature led to transformation of hexagonal celsian to monoclinic. The only glass frit containing 15wt% PbO had the crystal phase of solid solution of $PbTiO_3-CaTiO_3$. At the frequency of 1 MHz, the dielectric constant of glass frit crystallized was in the range of 11~16 and the dielectric loss less than 0.020. But the glass frit containing 15wt% PbO had the dielectric constant of 17~26 and loss of 0.010~0.015 because of crystal phase of solid solution of $PbTiO_3-CaTiO_3$.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.95-96
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• 2000

The effect of $Al_2O_3$ on the dielectric constant and the coefficient of thermal expansion of lead borosilicate glasses for the application of PDP glass paste was investigated. Measurements were made theoretically by using empirical equations on the composition of the of glasses in which the $PbO/Al_2O_3$, $B_2O_3/Al_2O_3$ and $SiO_2/Al_2O_3$ ratios were systematically varied. As a result, with increasing $PbO/Al_2O_3$ the thermal expansion coefficient and the dielectric constant noticeably increased, while the change of $B_2O_3/Al_2O_3$ and $SiO_2/Al_2O_3$ ratios did not affect those properties of the glasses.

• Proceedings of the Korean Ceranic Society Conference
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• 2000.04a
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• pp.33.1-33.1
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• 2000

• Journal of the Korean Ceramic Society
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• v.33 no.4
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• pp.385-390
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• 1996

The electrical resistivity of the ceramic glaze coated on ceramic substrate plays an important role on the characteristics of the thick and thin film electrical circuits. In this study the effects of the various modifiers on the electrical resistivity were examined in SiO2-Al2O3-B2O3-RO-Na2O (RO=CaO , SrO, BaO, PbO) glass system. In alkali free glasses where divalent cations are responsible for electrical conduction the electrical conductivity of th glasses increased with the ionic size of divalent cations due to the decrease in the bond strength between oxyben and divalent cation. In Na2O containing glasses however where Na+ ion is responsible for electrical conduction the ionic conductivity decreased with the ionic size of divalent cations because the blocking effect of the cations on Na+ ion movement increased with larger divalent cations. Na+ ionic conduction also depended on the glass structure relaxation due to the corrdination number changes of B2O3 and Al2O3 which varied with the NaO2 content in the glass.