• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.203-206
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• 2000

In this experiment, an attempt to use pellets($BaTiO_3$, $TiO_2$, ${\gamma}-Al_2O_3$, sludge) for $NO_x$ removal was conducted The effect of pellets on NO removal from simulated flue gas was experimentally investigated for packed-bed reactor of plate-plate geometry. An experimental investigation has been conducted for NO concentration of 50ppm balanced by air, and gas flow rate of $5{\ell}/min$. Ceramic pellets were used for surface discharge and the sludge pellets was added on $BaTiO_3$ and $TiO_2$ to increase $NO_x$ removal rate. In the result, $NO_x$ removal rate using $TiO_2$ was better than other pellets. $NO_2$ segnificatly generated by using $BaTiO_3$ pellets and sludge pellets used with $BaTiO_3$ decreased $NO_2$ generation.

• Journal of the Korean Ceramic Society
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• v.39 no.11
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• pp.1017-1022
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• 2002

$(Ba_{1-x}Ca_x)(Ti_{1-y}Zr_y)O_3(BCTZ)$ powders for the Ni-electrode Multilayer Ceramic Capacitor(MLCC) were synthesized via hydrothermal treatment using mixed aqueous solutions of $BaCl_2{\cdot}2H_2O,\Ca(NO_3)2{\cdot}4H_2O,\ ZrOCl_2{\cdot}8H_2O$ and $TiCl_4$. Two component and three component systems were also extensively studied for basic data. BT, CT and BZ powders were crystalline but CZ was determined to be amorphous under the same synthetic condition. In BTZ system, Zr and Ti were completely soluble and Ca would be substituted for Ba up to ∼6 mol% in BCT. The submicron-sized $(Ba_{0.95}Ca_{0.05})(Ti_{0.80}Zr_{0.20})O_3$ powder of the target composition was successfully synthesized at $150{\circ}$ for 12h.

• Journal of the Korean Ceramic Society
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• v.35 no.8
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• pp.864-870
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• 1998

The effect of {{{{ {{Nb }_{2 }O }_{5 } }} and CoO addition on the temperature dependence of the {{{{ {BaTiO }_{3 } }}-based ceramic capa-citor has been studied. X7R with moderate temperature dependence has been developed by means of pre-cisely controlled {{{{ {{Nb }_{2 }O }_{5 } }}/CoO ratio. Dielectric constant(K) and dissipation factor(DF) were 3500 and 1.5% respectively. As the content of {{{{ {{Nb }_{2 }O }_{5 } }} was increased the curie temperature(Tc) was shifted to lower tem-perature and the dielectric constant at Tc was decreased. The proper addition of CoO with {{{{ {{Nb }_{2 }O }_{5 } }} improved the temperature dependence of dielectric properties of the {{{{ {BaTiO }_{3 } }}-based ceramic capacitor.

• Journal of the Korean Ceramic Society
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• v.36 no.6
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• pp.590-598
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• 1999

• Journal of the Korean Ceramic Society
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• v.28 no.7
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• pp.525-530
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• 1991

The effects of 0.15mol% Y2O3 doped semiconducting (Ba1-xPbx)TiO3 ceramics with 0.5 mol% Pb5Ge3O11 as sintering additives have been investigated as function of Pb contents (from 0.05 mol to 0.3 mol) and sintering temperatures (from 1050$^{\circ}C$ to 1200$^{\circ}C$). As the Pb content increases in the (Ba1-xPbx)TiO3 system, the size and resistance of the grain increase but the capacitance of the grain boundary decreases due to the formation of liquid phase during the sintering. And with increasing the sintering temperatures, the resistance of the grain decreases but the capacitance of the grain boundary increases. The PTCR effects decrease with increasing the Pb content and the sintering temperature.

• Proceedings of the Materials Research Society of Korea Conference
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• 1993.11a
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• pp.119-120
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• 1993

• Proceedings of the Materials Research Society of Korea Conference
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• 1996.11a
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• pp.57-57
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• 1996

• Journal of the Korean Ceramic Society
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• v.32 no.8
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• pp.938-944
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• 1995

Dielectric properties and the stabilization of perovskite phase for the (1-y)Pb(Mg(1-x)/3Znx/3Znx/3Nb2/3)O3-yBaTiO3 ((1-y)PM1-xZxN-yBT) ceramics have been investigated as a function of amount of x and y. In the (1-y)PM0.6Z0.4N-yBT ceramics, the amount of pyrochlore phae was decreased by the addition of 2 mol% BT and the dielectric constant was increased. However, the dielectric constant decreased with further addition of BT even though pyrochlore phase was decreased. Dielectric prooperties in (1-y)PM0.6Z0.4N-yBT ceracmis were affected by the character of the BT rather than the amount of pyrochlore phase. The phase transitions were broadened and phase transition temperatures were lowered by the increase of BT contents.

• Journal of the Korean Ceramic Society
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• v.38 no.3
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• pp.245-250
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• 2001

BaO-TiO$_2$계의 TiO$_2$-rich 조성영역에 대한 상평형 관계를 완전 고상 반응법을 통하여 재평가하였다. 출발 시료로는 이 계의 end-member인 BaO와 TiO$_2$(rutile)를 이용하였다. 각 시료들은 대기 중에서 800~120$0^{\circ}C$의 온도구간에서 선택적으로 열처리되었다. 열처리된 시편들은 상온까지 급냉 처리되었으며, 상 분석은 X-ray 회절 분석을 통하여 이루어졌다. 연구결과에서 BaTi$_2$O$_{5}$(1:2)상과 BaTi$_{5}$O$_{11}$(1:5)상이 저온에서의 고상 반응을 통해서도 쉽게 형성될 수 있음을 알 수 있었으며, 각 저온 상들의 불변 반응 온도를 열처리 온도에 따른 상 분석을 통하여 확인할 수 있었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.73-76
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• 2001

We deposited epitaxial $Ba_{0.6}Sr_{0.4}TiO_{3}(BST)$ films having thickness of 400 nm on MgO(001) substrates, where a 10 nm thick $Ba_{1-x}Sr_{x}TiO_{3}$ (x = 0.1 - 0.7) interlayer was inserted between BST and MgO to manipulate the stress of the BST films. Since the main difference of those epitaxial BST films was the lattice constant of the interlayers, we were very successful in controlling the stress of the BST films. BST films under small tensile stress showed larger dielectric constant than that without stress as well as those under compressive stress. Stress relaxation was investigated using epitaxial BST films with various thicknesses grown on different interlayers. For BST films grown on $Ba_{0.7}Sr_{0.3}TiO_{3}$ interlayers, the critical thickness was about 600 nm. On the other hand, the critical thickness of single-layer BST film was less than 100 nm.