• 제목/요약/키워드: $BaTiO_3$ ceramics

검색결과 412건 처리시간 0.023초

카본블랙을 첨가하여 제조한 다공성 BaTiO3계 세라믹스의 미세구조 및 PTCR 특성 변화 (Microstructure and PTCR Characteristics of Porous BaTiO3-based Ceramics Prepared by Adding Carbon Black)

  • 이기주;당동욱;조원승
    • 한국분말재료학회지
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    • 제18권1호
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    • pp.41-48
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    • 2011
  • As a pore precursor, carbon black with different content of 0 to 60 vol% were added to (Ba,Sr)$TiO_3$ powder. Porous (Ba,Sr)$TiO_3$ ceramics were prepared by pressureless sintering at $1350^{\circ}C$ for 1h under air. Effects of carbon black content on the microstructure and PTCR characteristics of porous (Ba,Sr)$TiO_3$ ceramics were investigated. The porosity of porous (Ba,Sr)$TiO_3$ ceramics increased from 6.97% to 18.22% and the grain size slightly decreased from $7.51\;{\mu}m$ to $5.96\;{\mu}m$ with increasing carbon black contents. PTCR jump of the (Ba,Sr)$TiO_3$ ceramics prepared by adding carbon black was more than $10^5$, and slightly increased with increasing carbon black. The PTCR jump in the (Ba,Sr)$TiO_3$ ceramics prepared by adding 40 vol% carbon black showed an excellent value of $9.68{\times}10^5$, which was above two times higher than that in (Ba,Sr)$TiO_3$ ceramics. These results correspond with Heywang model for the explanation of PTCR effect in (Ba,Sr)$TiO_3$ ceramics. It was considered that carbon black is an effective additive for preparing porous $BaTiO_3$ based ceramics. It is believed that newly prepared (Ba,Sr)$TiO_3$ cermics can be used for PTC thermistor.

$BaTiO_3$ 세라믹스와 Oxide Setter의 반응성에 관한 연구 (Study on the Reaction between $BaTiO_3$ Ceramics and Oxide Setters)

  • 박정현;최현정;조경식;염강섭;조철구
    • 한국세라믹학회지
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    • 제31권6호
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    • pp.651-659
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    • 1994
  • BaTiO3 ceramics were sintered on Al2O3, MgAl2O4, MgO and Mg-, Ca-, Y-stabilized zirconia setters. Then the influence of setters on the microstructure of BaTiO3 ceramics and the stability of setters were investigated by SEM, EDAX and XRD analyses. The microstructure of BaTiO3 ceramics sintered on Al2O3, MgAl2O4, MgO and Mg-PSZ showed large grain growth, but little grain growth on Ce-TZP(Tetragonal Zirconia Policrystal). Mg-PSZ(Partially Stabilized Zirconia), Ca-PSZ, Ce-TZP setters showed extensive phase transformation. Y-TZP and fused Y-SZ (Stabilized Zirconia) setters were stable. The liquid sintering aids of BaTiO3 ceramics accelerate mass transport. The reaction of SrTiO3 in BaTiO3 with ZrO2 resulted in the formation of SrZrO3.

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소결온도에 따른 $BaTiO_{3}+10wt%Nb_{2}O_{5}$ 세라믹스의 구조 및 유전특성 (The Structural and dielectric Properties of the $BaTiO_{3}+10wt%Nb_{2}O_{5}$ ceramics with the sintering temperature)

  • 이상철;이성갑;배선기;이영희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.402-405
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    • 2001
  • The BaTiO$_3$+10wt%Nb$_2$O$_{5}$ ceramics were prepared by conventional mixed oxide method. The structural and dielectric properties of the BaTiO$_3$+10wt%Nb$_2$O$_{5}$ ceramics with the sintering temperature were investigated. Increasing the sintering temperature, the 2$\theta$ value of BaTiO$_3$peaks were shifted to the higher degree and intensity of the BaTiO$_3$and BaNbO$_3$peaks were increased. In the BaTiO$_3$+10wt%Nb$_2$O$_{5}$ ceramics sintered at 135$0^{\circ}C$ and 1375$^{\circ}C$, the grain was fine and uniform. Increasing the sintering temperature, the pore was decreased and the dielectric constant was increased. In the BaTiO$_3$+10wt%Nb$_2$O$_{5}$ ceramics sintered at 1375$^{\circ}C$, the dielectric constant and dielectric loss were 5424, 0.02 respectively.ctively.

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저온 소결에 의한 반도성 $BaTiO_3$ 세라믹스 제조에 관한 연구 (A Study on Fabrication of Semiconducting $BaTiO_3$ Ceramics at Lower Sintering Temperature)

  • 김준수;김흥수;권오성;이병하
    • 한국세라믹학회지
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    • 제33권2호
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    • pp.183-191
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    • 1996
  • For the fabrication of semiconducting BaTiO3 ceramics at lower sintering temperature BN was selected as a sintering aid and the microsturcture of semiconducting BaTiO3 ceramics and PTCR characteristics by their microstructural changes were investigated. by adding BN to 0.1 mol% Sb2O3-doped BaTiO3 ceramics the sintering temperature showing semiconducting BaTiO3 ceramics was reduced by 16$0^{\circ}C$ from 130$0^{\circ}C$ to 114$0^{\circ}C$ and the specific resistivity ratio was increased as the amount of BN was increased.

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$BaB_2B_4$ 첨가에 따른 반도성 $BaTiO_3$ 세라믹스의 소결 및 전기적 특성 (Sintering and Electrical Characteristics of Semiconducting $BaTiO_3$ Ceramics with Addition of $BaB_2O_4$)

  • 허영우;이준형;김정주;김남경;조상희
    • 한국세라믹학회지
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    • 제33권9호
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    • pp.1038-1044
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    • 1996
  • The variations of sintering and electrical characteristics of semiconducting BaTiO3 ceramics with sintering agents added were investigated comparing the case of BaB2O4 addition to BN and TiO2 addition. When BaB2O4 added in BaTiO3 ceramics the densitifcation of specimen could be acheived more easily and recvealed the better PTCR characteristics than BN and TiO2 addition. As increase of addition of BaB2O4 in BaTiO3 spec imens the slope of resistivity jump also increased but the temperature of maximum resistivity decreased, It was supposed that addition of BaB2O4 led to increase of Ns (acceptor state density) value at grain boundaries.

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소결온도에 따른 $BaTiO_3+Nb_2O_5$ 세라믹스 구조적 특성 (The Structural properties of $BaTiO_3+Nb_2O_5$ ceramics with sintering temperature)

  • 이상철;김지헌;김강;류기원;이영희
    • 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.

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CuO 첨가에 따른 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 세라믹스의 유전 이완 특성 (Dielectric Relaxation Properties of 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 Ceramics with CuO Addition)

  • 배선기;신혜경;이석진;임인호
    • 한국전기전자재료학회논문지
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    • 제28권2호
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    • pp.80-84
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    • 2015
  • We investigated the dielectric relaxation properties $0.5Ba(Zr_{0.2}Ti_{0.8})O_3-0.5(Ba_{0.7}Ca_{0.3})TiO_3$ ceramics with CuO addition. With increasing CuO addition, the lattice parameter was increased by substitution of small amount $Cu^{2+}$ ion in B-site of $0.5Ba(Zr_{0.2}Ti_{0.8})O_3-0.5(Ba_{0.7}Ca_{0.3})TiO_3$ ceramics. Also the grain size and the maximum dielectric constant of $0.5Ba(Zr_{0.2}Ti_{0.8})O_3-0.5(Ba_{0.7}Ca_{0.3})TiO_3$ ceramics was decreased with increasing amounts of CuO addition. Moreover, the diffused phase transition properties (${\gamma}$) of $0.5Ba(Zr_{0.2}Ti_{0.8})O_3-0.5(Ba_{0.7}Ca_{0.3})TiO_3$ ceramics was increased by compositional fluctuation with increasing of CuO amount, changed from 1.45 at 1 wt% CuO addition to 1.94 at 7 wt% CuO addition.

$BaTiO_{3}+xNb_{2}O_{5}$ 세라믹스의 구조 및 유전특성 (The stuctural and dielectric properties of the $BaTiO_{3}+xNb_{2}O_{5}$ ceramics)

  • 이상철;류기원;이성갑;이영희
    • 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.

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$BaTiO_{3}+xNb_{2}O_{5}$ 세라믹스의 구조 및 유전특성 (The structural and dielectric properties of the $BaTiO_{3}+xNb_{2}O_{5}$ ceramics)

  • 이상철;류기원;이성갑;이영희
    • 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.

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소결온도에 따른 $0.98MgTiO_3-0.02BaTiO_3$ 세라믹스의 마이크로파 유전특성 (Microwave Dielectric Properties of the $0.98MgTiO_3-0.02BaTiO_3$ Ceramics with Sintering Temperature)

  • 최의선;이문기;이성갑;배선기;이영희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 연구회
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    • pp.123-126
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    • 2001
  • The $0.98MgTiO_3-0.02BaTiO_3$ ceramics were prepared by the conventional mixed oxide method. The structural properties were investigated with sintering temperature and composition ratio by XRD, SEM and EDS. According to the X-ray diffraction patterns of the $0.98MgTiO_3-0.02BaTiO_3$ ceramics, the hexagonal $BaMg_6Ti_6O_{19}$ and ilmenite $MgTiO_3$ structures were coexisted. The dielectric constant$({\varepsilin}_r)$ and quality factor$(Q{\times}f_r)$ were decreased with increasing the sintering temperature in the range of $1275^{\circ}C{\sim}1350^{\circ}C$. In the case of the $0.98MgTiO_3-0.02BaTiO_3$ ceramics sintered at $1275^{\circ}C$, dielectric constant, quality factor and temperature coefficient of resonant frequency were 20.27, 76,845, $-46.6ppm/^{\circ}C$, respectively.

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