• 제목/요약/키워드: Barium Titanate Ceramics

검색결과 60건 처리시간 0.031초

Effect of the Sintering Temperature on Electrical Properties of Porous Barium-strontium Titanate Ceramics

  • Kim, Jun-Gyu;Sim, Jae-Hwang;Cho, Won-Seung
    • 한국세라믹학회지
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    • 제40권1호
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    • pp.5-10
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    • 2003
  • Porous barium-strontium titanate ceramics were fabricated by adding corn- or potato-starch (are referred to as starch). The effect of sintering temperature on the microstructure and electrical properties of the porous ceramics was investigated. The room-temperature electrical resistivity of the barium-strontium titanate ceramics decreased with sintering temperature. The porosity and pore size were decreased and the grain size was increased with increasing the sintering temperature. The porosity and grain size of the barium-strontium titanate ceramics with corn-starch sintered at 1300 and 1450$^{\circ}C$ were 28.5, 22.6% and 3.2, 6.2 $\mu\textrm{m}$, respectively. The average pore sizes of the barium-strontium titanate ceramics with corn-starch sintered at 1300, 1400 and 1450$^{\circ}C$ were 0.5, 0.3 and 0.2 $\mu\textrm{m}$, respectively. The decrease in the room-temperature resistivity with increasing sintering temperature is attributed mainly due to the increase of grain size and the decrease of the electrical barrier height of grain boundaries as well as the partial decrease of porosity.

$BaTiO_3$ 세라믹의 절연파괴거동에 미치는 기공의 크기와 기공율의 영향 (Effect of pore size and porosity on electrical breakdown behaviors of $BaTiO_3$ ceramics)

  • 조경호;우동찬;남효덕;이희영
    • E2M - 전기 전자와 첨단 소재
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    • 제10권3호
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    • pp.255-261
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    • 1997
  • In this study, pore-containing barium titanate ceramics were prepared with different porosities and pore sizes, in order to better understand how porosity and pore size affect electrical breakdown of barium titanate ceramics. A granulated barium titanate powder was mixed with three grades of commercial polymer microspheres up to 11wt%. The electrical breakdown test was performed at two different temperatures of 30.deg. C(below Tc) and 150.deg. C(above Tc) for samples immersed in a silicon oil bath using a 60kV de power supply. Electrical breakdown strength of pore containing barium titanate ceramics with porosity lower than 10% decreased as pore size and porosity increased. However, above the 10% porosity region, electrical breakdown strength decreased as the pore connectivity increased. From the experimental results, an optimum electrical breakdown model is proposed in an attempt to explain the effect of pores.

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[100]-Texturing of Barium Titanate Ceramics Using Sodium Bismuth Titanate Templates: Challenges and Insights

  • Nu-Ri Ko;Temesgen Tadeyos Zate;Wook Jo
    • 한국전기전자재료학회논문지
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    • 제37권3호
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    • pp.328-331
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    • 2024
  • This research explores the development of [100]-textured barium titanate (BaTiO3, BT) ceramics using sodium bismuth titanate (Na0.5Bi4.5Ti4O15, NBiT) templates, aimed at leveraging the inherent high dielectric property of BT. However, the attempted texturing was unsuccessful, primarily due to bismuth diffusion from the NBiT templates into the BT matrix below the sintering temperature, at 1,000℃. Systematical exploration about the cause of the failure is involved and alternative approaches are proposed in detail to overcome the challenge. These findings contribute to the understanding of techniques and conditions for textured ceramic fabrication and highlight the need for further research in this area.

O-3형 BaTiO3-폴리머 복합체의 계면기공율 변화에 따른 유전 및 압전특성 (Effects of Interface Porosity on Dielectric and Piezoelectric Properties of BaTiO3-Polymer Composites of O-3 Type Connectivity)

  • 이형규;김호기
    • 한국세라믹학회지
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    • 제26권5호
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    • pp.617-624
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    • 1989
  • Piezoelectric composites of O-3 connectivity were prepared by thermosetting barium titanate-phenolic resin composite under various cruing pressure. Among three kinds of pore in O-3 type ceramic-polymer composite, such as matrix pores, particle pores, and ceramic-polymer interface pores, the effect of interface porosity on the dielectric and piezoelectric constant was investigated. In pure barium titanate ceramics, the porosity factor of dielectric and piezoelectric constants were 5.7 and 5.0, respectively. However, in BaTiO3-polymer composite, the interface porosity factor of the piezoelectric constant was greater than that of the dielectric constant, interface porosity factor b in d33 was 9.8 and in r 4.6. On the other, piezoelectric voltage constant g33 was independent of the porosity of barium titanate ceramics. But in composite system, the piezoelectric voltage constant g33 was decreased with interface porosity.

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Thermal Shock Behavior of Barium Titanate Ceramics

  • Jae Yeon Kim;Young Wook Kim;Kyeong Sik Cho;June Gunn Lee
    • The Korean Journal of Ceramics
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    • 제3권3호
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    • pp.195-198
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    • 1997
  • Post-firing process of electronic ceramic, such as electroding and encapsultion with resin, often causes damage by thermal shock. The thermal shock behavior of $BaTiO_3$ ceramics was investigated by the down-quench test, where the relative strength retained is determined after the sample is quenched from an elevated temperature into a fixed temperature bath. The critical temperature drop, $\DeltaTc$, was evaluated for three kinds of sintered $BaTiO_3$ ceramics, which were formed by extrustioin, uniaxial pressing using granules, and uniaxial pressing using powders. A drastic loss in strength caused by microcracking was observed for the specimens quenched with $\DeltaT\geq150^{\circ}C$. This concentp can be adopted as a method of the quality control by monitoring the sudden drop of the strength of capacitor products after each exposure to heat.

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EFFECT of PREPARATION METHODS and CONDITIONS of PRECURSORS on the PROPERTIES of $BATIO_3$ ALKOXIDE FILMS

  • N., Korobova;Soh, Dea-Wha
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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    • pp.714-718
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    • 2003
  • Usually for the commercial preparation of barium titanate films or ceramics the reaction atmosphere must be preferably in air. However, normally air is not used because it contains carbon dioxide, which can easily react with barium to form the undesired product barium carbonate, leading to unwanted second-phase formation in the (mal stages of the process. In the present work a series of perovskite barium titanate films was prepared by the sol-gel method, using a metal alkoxide solutions in the electrophoretic deposition (EPD). The influence of several process parameters, like sintering temperature of sol preparation before EPD and heat-treatment temperature and non-oxidized atmosphere, on the film properties is described.

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Highly Donor-doped LaxBa1-xTiO3 Ceramics

  • Korobova Nataly;Soh Dea-Wha
    • Transactions on Electrical and Electronic Materials
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    • 제4권4호
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    • pp.18-21
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    • 2003
  • Sol-gel processing of $BaTiO_3$ ceramics doped with La(0.01-1.00 at. $\%$) were prepared from metal barium, titanium n-butoxide and lanthanum iso-propoxide. Characterization of the sol-gel-derived powder using XRD, SEM is also reported. The obtained results showed that insulator to semiconductor transition for highly donor-doped barium titanate was closely related to the incorporation of donor into the grains and to the resultant grain size, which were significantly affected by the sinterability of $BaTiO_3$ powders and sintering conditions used.

Lanthanum doped $BaTiO_3$ ceramics

  • Korobova, N.;Soh, Dea-Wha
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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    • pp.287-290
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    • 2003
  • Sol-gel processing of $BaTiO_3$ ceramics doped with La(0.01~1.00 at.%) were prepared from metal barium, titanium n-butoxide and lanthanum iso-propoxide. Characterization of the sol-gel-derived powder using XRD, SEM is also reported. The obtained results showed that insulator to semiconductor transition for highly donor-doped barium titanate was closely related to the incorporation of donor into the grains and to the resultant grain size, which were significantly affected by the sinterability of $BaTiO_3$ powders and sintering conditions used.

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강유전체에서의 전계분포 및 절연파괴 (Dielectric Breakdown and Electric Stress Distribution in Ferroelectrics)

  • 신병철;김호기
    • 한국세라믹학회지
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    • 제24권4호
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    • pp.392-396
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    • 1987
  • Pure barium titanate was sintered at $1340^{\circ}C$ for 2, 4, 8, 16 hr to control their grain size. The measurements of breakdown strength and partial discharge characteristics were performed under rising AC voltage(60Hz). With increase of sintering time, the average grain size was increased and breakdown strength was slightly decreased. Partial discharge in pores was observed under high voltage, and a model of dielectric break down in barium titanate ceramics is proposed.

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