• 한국재료학회지
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• 제5권8호
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• pp.1026-1034
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• 1995

저손실 망간징크 페라이트에서 CaO-SiO$_2$첨가는 입계에 높은 전기저항층을 형성시켜 와류에 의한 손실을 감소시키는 것으로 알려져 있다. 본 실험에서는 Nb$_2$O$_{5}$ 를 제 3의 첨가제로 사용하여 저손실 망간징크 페라이트에서의 전자기적 물성변화를 관찰하였다. Nb$_2$O$_{5}$ 300ppm 이상 첨가시 부분적인 과대입자 성장이 관찰되었으며, 200ppm 첨가시 CaO-SiO$_2$만 첨가한 시편에 비하여 밀도가 증가하였다. Nb$_2$O$_{5}$ 첨가시에는 100ppm 이하의 SiO$_2$첨가에서 우수한 전력손실 특성이 나타났으며, 고온 소결시 Nb$_2$O$_{5}$-CaO를 첨가한 시편에서 낮은 전력손실을 나타내었다.

• 한국세라믹학회지
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• 제19권4호
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• pp.267-274
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• 1982

The sintering behavior and B-H loop properties of $Li_{0.5O4}$ with the addition of $Nb_2O_5$ and $V_2O_5$ have been investigated by observation of microstructures and measurement of semi-static hysteresis loops. The sintering temperature was lowered by the additions of $Nb_2O_5$ and $V_2O_5$ and the effect of $V_2O_5$ addition was greater than that of $Nb_2O_5$. The abnormal grain growth was observed at about 100$0^{\circ}C$(d:4.6g/㎤) and 85$0^{\circ}C$(d:4.5g/㎤) in the specimens with the addition of $Nb_2O_5$ and $V_2O_5$ respectively. The addition of $Nb_2O_5$ retulted in a large and uniform grain size, and the addition of $V_2O_5$ resulted in a uniform grain size but the final density was lower than that of the pure specimen. The squareness was increased and the coercive force was decreased by the addition of $Nb_2O_5$, and the squareness was decreased and the coercive force was increased by the addition of $V_2O_5$. These effects could be explained by a large and uniform grain size, and by a lower final density of specimens with the addition of $Nb_2O_5$ and $V_2O_5$ respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 연구회
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• pp.127-130
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• 2001

The $BaTiO_3+xNb_2O_5$(x=6, 8, 10wt%) ceramics were prepared by conventional mixed oxide method. The structural properties of the $BaTiO_3+Nb_2O_5$ ceramics with the sintering temperature and addition of $Nb_2O_5$ were investigated by XRD and SEM. Increasing the sintering temperature, the $2{\theta}$ value of BT(110) peak was shifted to the lower degree and intensity of the $Ba_6Ti_2Nb_8O_{30}$ (133) peak was increased. Increasing the addition of $Nb_2O_5$, the intensity of $BaTiNb_4O_{13}$ (201) peak was decreased and $Ba_6Ti_2Nb_8O_{30}$ (133) peak was increased. The grain size of the $BaTiO_3+Nb_2O_5$ ceramics sintered at $1500^{\circ}C$ were almost uniform.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.280-283
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• 2002

In this study, the effects of $Nb_{2}O_{5}$ addition on microstructure and piezoelectric characteristics of PNW-PMN-PZT ceramics were investigated. As $Nb_{2}O_{5}$ addition amount is increased, grain size is gradully decreased. At 0.3wt%$Nb_{2}O_{5}$ addition composition ceramics, maximum density, tetragonality and piezoelectric characteristics were obtained.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.798-801
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• 2004

In this study, in order to develop low temperature sintering ultrasonic vibrator, PCW-PMN-PZT ceramics with the amount of $Nb_2O_5$ addition were manufactured. All of the fabricated sample showed pure pervoskite structure of tetragonal phase. With increasing the amount of $Nb_2O_5$ addition, mechanical quality factor Qm were increased up to 0.2wt%$Nb_2O_5$ addition and then decreased. And also, with increasing the amount of $Nb_2O_5$ addition, grain size, kp, density and dielectric constant were linearly decreased. At the 0.2wt% $Nb_2O_5$ addition composition ceramic, kp of 0.48, Qm of 2186, ${\varepsilon}r$ of 1219 were shown, respectively. Their values were suitable for ultrasonic vibrator application.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.426-429
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• 2001

The $BaTiO_{3}+xNb_{2}O_{5}$[x=6, 8, 10wt%] ceramics were prepared by conventional mixed oxide method. The structural properties of the $BaTiO_{3}+xNb_{2}O_{5}$ ceramics with the sintering temperature and addition of $Nb_{2}O_{5}$ were investigated by XRD and SEM. Increasing the sintering temperature, the $2{\Theta}$ value of BT (110) peak was shifted to the lower degree and intensity of the BN (310) peak was increased. Increasing the addition of $Nb_{2}O_{5}$, the intensity of BN (100) peak was decreased and BN (310), (110) peaks were increased. The grain size of the $BaTiO_{3}+xNb_{2}O_{5}$ ceramics sintered at $1350^{\circ}C$ were almost uniform. In the $BaTiO_{3}+xNb_{2}O_{5}$ ceramics sintered at $1350^{\circ}C$, the dielectric constant and dielectric loss were 5424, 0.02 respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.426-429
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• 2001

The BaTiO$_3$+xNb$_2$O$_{5}$[x=6,8 , 10wt%] ceramics were prepared by conventional mixed oxide method. The structural properties of the BaTiO$_3$+xNb$_2$O$_{5}$ ceramics with the sintering temperature and addition of Nb$_2$O$_{5}$ were investigated by XRD and SEM. Increasing the sintering temperature, the 2$\theta$ value of BT (110) peak was shifted to the lower degree and intensity of the BN (310) peak was increased. Increasing the addition of Nb$_2$O$_{5}$, the intensity of BN (100) Peak was decreased and BN (310), (110) peaks were increased. The grain size of the BaTiO$_3$+Nb$_2$O$_{5}$ ceramics sintered at 135$0^{\circ}C$ were almost uniform. In the BaTiO$_3$+Nb$_2$O$_{5}$ ceramics sintered at 135$0^{\circ}C$, the dielectric constant and dielectric loss were 5424, 0.02 respectively.espectively.

• 한국세라믹학회지
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• 제35권8호
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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.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권7호
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• pp.347-351
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• 2004

The $ZnNb_2O_{6}$ ceramics with CuO(1, 3, 5wt%) were prepared by the conventional mixed oxide method. The ceramics were sintered at the temperature of $950^{\circ}C$∼$1075^{\circ}C$ for 3hr in air The structural properties and the microwave dielectric properties of $ZnNb_2O_{6}$ ceramics were investigated with sintering temperature and the addition of CuO. Increasing the addition of CuO, the peak of second phase($Cu_3Nb_2O_{8}$) was increased. The grain size of the $ZnNb_2O_{6}$ ceramics with CuO was increased with CuO addition at same temperature. The dielectric constant of $ZnNb_2O_{6}$ ceramics with CuO was increased with sintering temperature and CuO addition. While the quality factor of the $ZnNb_2O_{6}$ ceramics with lwt% CuO depended on sinterability, the quality factor of $ZnNb_2O_{6}$ with 3wt% and 5wt% CuO depended on second Phase due to the CuO addition. The optimum dielectric Properties of $\varepsilon$$_{r}$ = 21.73 Q${\times}$f = 19,276 were obtained from the condition of 3wt% CuO addition and sintering temperature of $1025^{\circ}C$(3hr).

• 한국결정학회지
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• 제17권1호
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• pp.24-32
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• 2006

[ $Zn_3Nb_2O_8$ ]세라믹스에 액상소결제인 $V_2O_5$를 첨가하여 소결하여 고주파 대역에서의 유전특성의 변화를 조사하였다. $1100^{\circ}C$에서 2시간 하소한 결과 $Zn_3Nb_2O_8$를 합성할 수 있었고, $V_2O_5$를 첨가하여 소결한 $Zn_3Nb_2O_8$에서 $V_2O_5$의 mole%증가와 소결온도의 증가에 따라 상대밀도 95%의 소결특성을 확인 하였다. 유전율 특성은 $V_2O_5$ mole ratio가 $2{\sim}4%$의 시편에서 모두 ${\varepsilon}_r\;21$ 이상으로 증가됨을 확인하였고, 품질계수는 $900^{\circ}C$에서 소결한 $V_2O_5$ 2 mole% 시편에서 $Q{\times}f=40,000$을 나타내었다. 온도계수는 $900^{\circ}C$ 소결하고 $V_2O_5$ 1 mole% 첨가한 경우 0에 제일 가까운 $T_{cf}=-54ppm/^{\circ}C$를 나타내었고, 다른 보건에서는 $T_{cf}=-60{\sim}-80ppm/^{\circ}C$의 값을 나타내었다.