• Title, Summary, Keyword: TCC(Temperature coefficient capacitance)

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TCC behavior of a shell phase in core/shell structure formed in Y-doped BaTiO3: an individual observation (Yttrium이 첨가된 BaTiO3에서 형성된 core/shell 구조에서 shell의 TCC 거동: 독립적 관찰)

  • Jeon, Sang-Chae
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.30 no.3
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    • pp.110-116
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    • 2020
  • Grains in the BaTiO3, which is used for a dielectric layer in MLCC(Multi-Layer Ceramic Capacitor) are necessary to form core/shell structure for a stable TCC(Temperature Coefficient of Capacitance) behavior. The shell property has been deduced from the whole TCC behavior of core/shell structure due to its tiny size, ~ few ㎛. This study demonstrates the individual TCC behavior of the shell phase measured by micro-contact measurement in a temperature range between 35 and 135℃. Pt electrode pairs deposited on an enlarged core/shell structure in a diffusion couple sample made the measurement possible. As a result, the DPT (Diffusion Phase Transition) behavior of the shell phase was revealed as a different TCC behavior from that of the core: a broad peak with Tm at 65℃. This would be also useful experimental data for a modelling that depicts dielectric-temperature behavior of core/shell structure.

Polymorphic Phase Transition and Temperature Coefficient of Capacitance of Alkaline Niobate Based Ceramics

  • Bae, Seon-Gi;Shin, Hyea-Gyiung;Sohn, Eun-Young;Im, In-Ho
    • Transactions on Electrical and Electronic Materials
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    • v.14 no.2
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    • pp.78-81
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    • 2013
  • $0.95(Na_{0.5}K_{0.5})NbO_3-0.05BaTiO_3+0.2wt%\;Ag_2O$ (hereafter, No excess NKN) ceramics and $0.95(Na_{0.5}K_{0.5})NbO_3-0.05BaTiO_3+0.2wt%\;Ag_2O$ with excess $(Na_{0.5}K_{0.5})NbO_3$ (hereafter, Excess NKN) were fabricated by the conventional solid state sintering method, and their phase transition properties and dielectric properties were investigated. The crystalline structure of No excess NKN ceramics and Excess NKN ceramics were shown characteristics of polymorphic phase transition (hereafter, PPT), especially shift from the orthorhombic to tetragonal phase by increasing sintering temperature range from $1,100^{\circ}C$ to $1,200^{\circ}C$. Also, the temperature coefficient of capacitance (hereafter, TCC) of No excess NKN ceramics and Excess NKN ceramics from $-40^{\circ}C$ to $100^{\circ}C$ was measured to evaluate temperature stability for applications in cold regions. The TCC of No excess NKN and Excess NKN ceramics showed positive TCC characteristics at a temperature range from $-40^{\circ}C$ to $100^{\circ}C$. Especially, Excess NKN showed a smaller TCC gradient than those of Excess NKN ceramics in range from $-40^{\circ}C$ to $100^{\circ}C$. Therefore, NKN piezoelectric ceramics combined with temperature compensated capacitor having negative temperature characteristics is desired for usage in cold regions.

Dependence of Physical, and Electrical Properties of $CaTiO_3$ on Sintering Temperature and Composition ($CaTiO_3$ 유전 재료의 소결온도와 조성변화에 따른 물리적 및 전기적 특성 변화)

  • 우성수;안영수;한문희;노광수
    • Journal of the Korean Ceramic Society
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    • v.32 no.10
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    • pp.1111-1116
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    • 1995
  • To use dielectric material of high power multilayer capacitor, the composition of the commercial CaTiO3 was changed to decrease the sintering temperature, and the physical and electrical properties were investigated. Series of experiments showed that CaTiO3 with sintering additives had the highest density, the highest shrinkage, the lowest dielectric constant, the lowest loss factor, and the lowest temperature coefficient of capacitance (TCC). These properties had the constant values at sintering temperature of above 120$0^{\circ}C$.

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Preparation of Zr0.7Sn0.3TiO4 Thin Films by Metal Organic Decomposition and Their Dielectric Properties (금속유기분해법을 사용한 Zr0.7Sn0.3TiO4 박막 제조 및 유전특성)

  • Sun, Ho-Jung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.4
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    • pp.311-316
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    • 2010
  • $Zr_{0.7}Sn_{0.3}TiO_4$ (ZST) thin films were fabricated by metal-organic decomposition, and their dielectric properties were investigated in order to evaluate their potential use in passive capacitors for rf and analog/mixed signal integrated circuits. The ZST thin film annealed at the temperature of $800^{\circ}C$ showed a dielectric constant of 27.3 and a dielectric loss of 0.011. The capacitor using the ZST film had quadratic and linear voltage coefficient of capacitance (VCC) of -65 ppm/$V^2$ and -35 ppm/V at 100 kHz, respectively. It also exhibited a good temperature coefficient of capacitance (TCC) value of -32 ppm/$^{\circ}C$ at 100 kHz.

Crystalline Phases and Dielectric Properties of Crystallized Glasses in the System (Ca, Sr, Ba) O-Al2O3-B2O3-SiO2-TiO2

  • Tuzuku, Koichiro;Kishi, Hiroshi;Taruta, Seiichi;Takusagawa, Nobuo
    • The Korean Journal of Ceramics
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    • v.5 no.2
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    • pp.189-194
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    • 1999
  • Crystallization of glasses in the system (Ca, Sr, Ba)$O-Al_2O_3-B_2O_3-SiO_2-TiO_2$ and dielectric properties of crystallized glasses were investigated. As increasing B2O3 content and decreasing SiO2 content in the glass, the major crystalline phase changed from $(Sr, Ba)_2TiSi_2O_8$ to (Ca, Sr, Ba)TiO3, the dielectric constant of crystallized glasses increased and the Temperature Coefficient of Capacitance (TCC) changed to negative. The dielectric constant and TCC was estimated for (Sr, Ba)2TiSi2O8 phase as 18 and -440 $ppm/^{\circ}C$, respectively and for (Ca, Sr, Ba)TiO3 phase as 307 and -1900 $ppm/^{\circ}C$, respectively. The dielectric properties of (Ca, Sr, Ba)TiO3 phase (in this study) were similar to those of (Ca, Ba) TiO_3 solid-solution^12)$, but $(Sr, Ba)_2TiSi_2O_8$ phase (in this study) and $Sr_2TiSi_2O_\;8^4$ showed the different properties.

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The Dielectrical Properties of $(1-x)(Sr_a.Pb_b.Ca_c)TiO_3-xB_i2O_3.TiO_2$ system affected by $Bi_2O_3.3TiO_2$ amounts and $MnO_2$ ($(1-x)(Sr_a.Pb_b.Ca_c)TiO_3-xB_i2O_3.TiO_2$계에서의 $Bi_2O_3.3TiO_2$$MnO_2$첨가에 따른 유전특성에 관한 연구)

  • 박상도;이응상
    • Journal of the Korean Ceramic Society
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    • v.34 no.2
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    • pp.123-130
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    • 1997
  • In this study, (Sr.Pb.Ca)TiO3-Bi2O3.3TiO2(SPCT) systems were investigated to develop a new material which has a high dielectric constant, a low dielectric loss and a small TCC(Temperature Coefficient of Capa-citance), and are suitable for high voltage applications as a function of the additions of Bi2O3.3TiO2 from 5 mol.% to 9 mol.%. The result obtained from our investigation showed that up to 6 mol.% Bi2O3.3TiO ad-dition the dielectric constant increased and it deteriorated at higher concentrations with increasing amount of the acicular grains. As a result of some dopants (SiO2, Nb2O3, MnO2) addition to SPCT, the specimens with MnO2 showed good dielectric properties. The dielectric constant decreased, but the TCC was improved with the addition of MnO2 from 0.15 wt.% to 0.45 wt. %.

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Dielectric Properties and Microstructure of Modified $CaZrO_3$ for Application of Ni-MLCC with NPO Temperature Characteristics (NPO 온도특성의 Ni-MLCC 응용을 위한 CaZrO3의 유전특성 및 미세구조)

  • Chun, Myoung-Pyo;Myoung, Seong-Jae;Han, Ik-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.30-32
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    • 2005
  • The effects of mole ratio and Ti-ion on the dielectric properties and microstructure of modified $CaZrO_3$ composition such as $(Ca_{0.7}Sr_{0.3})_m(Ti_yZr_{1-y})O_3$ were investigated. Ti ions substituted on Zr-sites in these modified $CaZrO_3$ composition strongly affect the sintering density and microstructure of the fired ceramic body. With increasing the amount of Ti substituted on Zr-sites, the sintered density rapidly increased and the dense microstructures were obtained for the compositions having mole ratio of 1.01, whereas the sintered density and microstructures are nearly constant with the content of Ti-ion for the compositions having mole ratio of 0.99. With increasing the content of Ti ion, the curve of TCC (temperature coefficient of capacitance) as a function of temperature rotated clockwise and satisfied the COG characteristics for both of compositions with mole ratio of 0.99 and 1.01. The content of Ti ion seems to be more effective than mole with respect to the controlling of firing and TCC.

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Electrical Properties of the Amorphous BaTi4O9 Thin Films for Metal-Insulator-Metal Capacitors (Metal-Insulator-Metal 캐패시터의 응용을 위한 비정질 BaTi4O9 박막의 전기적 특성)

  • Hong, Kyoung-Pyo;Jeong, Young-Hun;Nahm, Sahn;Lee, Hwack-Joo
    • Korean Journal of Materials Research
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    • v.17 no.11
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    • pp.574-579
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    • 2007
  • Amorphous $BaTi_4O_9$ ($BT_4$) film was deposited on Pt/Si substrate by RF magnetron sputter and their dielectric properties and electrical properties are investigated. A cross sectional SEM image and AFM image of the surface of the amorphous $BT_4$ film deposited at room temperature showed the film was grown well on the substrate. The amorphous $BT_4$ film had a large dielectric constant of 32, which is similar to that of the crystalline $BT_4$ film. The leakage current density of the $BT_4$ film was low and a Poole-Frenkel emission was suggested as the leakage current mechanism. A positive quadratic voltage coefficient of capacitance (VCC) was obtained for the $BT_4$ film with a thickness of <70 nm and it could be due to the free carrier relaxation. However, a negative quadratic VCC was obtained for the films with a thickness ${\geq}96nm$, possibly due to the dipolar relaxation. The 55 nm-thick $BT_4$ film had a high capacitance density of $5.1fF/{\mu}m^2$ with a low leakage current density of $11.6nA/cm^2$ at 2 V. Its quadratic and linear VCCs were $244ppm/V^2$ and -52 ppm/V, respectively, with a low temperature coefficient of capacitance of $961ppm/^{\circ}C$ at 100 kHz. These results confirmed the potential suitability of the amorphous $BT_4$ film for use as a high performance metal-insulator-metal (MIM) capacitor.

The Electrical Properties of High Voltage Mutilayer Chip Capacitor with X7R by addition of Er2O3 and Glass Frit (고압용 X7R 적층 칩 캐패시터의 Er2O3 및 유리프릿 첨가에 따른 전기적 특성)

  • Yoon, Jung-Rag;Kim, Min-Kee;Chung, Tae-Seog;Woo, Byoung-Chul;Lee, Seog-Won
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.5
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    • pp.440-446
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    • 2008
  • To manufacture the MLCC with X7R for high voltage stability, $BaTiO_3-MgO-MnO_2-Y_2O_3$ with $(Ba_{0.4}Ca_{0.6})SiO_3$ glass frit was formulated. Based on this composition, the addition of $Er_2O_3$ showed that TCC(Temperature Coefficient Capacitance) at $85^{\circ}C$ was improved from 5 % to ${\sim}0\;%$, but the dielectric constant and IR (Insulation Resistance) were decreased. The glass frit improved the dielectric constant and IR, so the appropriate contents of $Er_2O_3$ and glass frit were 0.6 mol% and 1 wt%, respectively. It showed that the dielectric constant and RC constant were 2,550 and 2,000 (${\Omega}F$), respectively in the sintering condition at $1250^{\circ}C$ in PO2 $10^{-7}$ Mpa. The MLCC with $3.2{\times}1.6$ (mm) size and $1\;{\mu}F$ was also suited for X7R with the above composition.

Electrical properties and microstructure of microwave dielectric ceramics (Ca0.7Sr0.3)m(TiyZr1-y)O3 (고주파 유전체 세라믹 (Ca0.7Sr0.3)m(TiyZr1-y)O3의 전기적 특성 및 미세구조)

  • Chun, Myoung-Pyo;Park, Myoung-Sung;Kang, Kyung-Min;Nam, Joong-Hee;Cho, Jeong-Ho;Kim, Byung-Ik
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.20 no.1
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    • pp.21-24
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    • 2010
  • The effects of mole ratio(A/B) m and Ti-ion on the dielectric properties and microstructure of the microwave dielectric ceramics $(Ca_{0.7}Sr_{0.3})_m(Ti_yZr_{1-y})O_3$ were investigated. Ti ions substituted on Zr-sites in these modified $CaZrO_3$ composition strongly affect the sintering density and microstructure of the fired ceramic body. With increasing the amount of Ti substituted on Zr-sites, the sintered density rapidly increased and the dense microstructure was obtained for the compositions having mole ratio of 1.01, whereas the sintered density and microstructure are nearly constant with the content of Ti-ion for the compositions having mole ratio of 0.99. With increasing the content of Ti ion, the curve of TCC (Temperature Coefficient of Capacitance) as a function of temperature rotated clockwise and satisfied the COG characteristics for both of compositions with mole ratio of 0.99 and 1.01. The content of Ti ion seems to be more effective than mole with respect to the controlling of firing and TCC.