• E2M - 전기 전자와 첨단 소재
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• 제9권10호
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• pp.991-1000
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• 1996

PbTiO$_{3}$-PbZrO$_{3}$-Pb(Ni$_{1}$3/Nb$_{2}$3/O$_{3}$) (PZT-PNN) thin films were prepared from corresponding metal organics partially stabilized with diethanolamine by the sol-gel spin coating method. Each mol ratio of PT:PZ:PNN solutions were #1(50:40:10), #2(50:30:20), #3(45:35:20), #4(40:40:20), #5(40:50:10), #6(35:45:20) and #7(30:50:20) respectively. The spin-coated PZT-PNN films were heat-treated at 350.deg. C for decomposition of residual organics, and were sintered from 450.deg. C to 750.deg. C for crystallization. The substrates, such as Pt and Pt/TiN/Ti/TiN/Si were used for the spin coating of PZT PNN films. The perovskite phase was observed in the PZT-PNN films heat-treated at 500.deg. C. The crystalline of the PZT-PNN films was optimized at the sintering of 700.deg. C. By the result of AES analysis, It is confirmed that the films of TiN/Ti/TiN was a good diffusion barrier and that co-diffusion into the each films was not observed.

• The Korean Journal of Ceramics
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• 제2권3호
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• pp.162-166
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• 1996

The effects of NiO addition on the microstructure and microwave dielectric properties of ($Zr_{08}Sn_{02}$)$TiO_4$ (ZST) were investigated. With the NiO addition, a higher density of ZST ceramics than 95% of the theoretical values has been obtained in the sintering temperature range of 1400 to 150$0^{\circ}C$. Energy dispersive X-ray spectrometry (EDS) analysis of sintered specimen shows the presence of second phase at grain boundaries, which is considered to be $NiTiO_3$. Dielectric constant of the specimen is found to increase linearly with density. Q-values and TC$_r$ decrease with increasing NiO content. The variation of dielectric properties with NiO content is discussed in terms of the second phase. The ZST ceramics with 0.25 wt% NiO showed ${\varepsilon}_{\gamma}$=38, Q=7000 at GHz and TC$\gamma$=-0.5 ppm/$^{\circ}C$, comparable with the values obtained by the previous investigations.

• Bulletin of the Korean Chemical Society
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• 제24권2호
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• pp.159-160
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• 2003

• 한국표면공학회지
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• 제34권5호
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• pp.499-502
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• 2001

Functionally gradient NiCrAlY/$ZrO_2$-$Y_2$$O_3$ and NiCrAlY/$ZrO_2$- $CeO_2$-$Y_2$$O_3$ coatings were prepared by APS. The as-sprayed microstructure consisted of metal-rich and ceramic-rich regions, between which $Al_2$$O_3$-rich layers existed owing to the oxidation during APS. During oxidation between 900 and $1100^{\circ}C$ in air, the pre-existing $Al_2$$O_3$-rich scales grew, due mainly to the preferential reaction of Al with inwardly transporting oxygen along the heterogeneous phase boundaries. As the amount of ceramics in the coating increased, the oxidation resistance increased.

• 한국세라믹학회지
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• 제45권11호
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• pp.701-706
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• 2008

High frequency dielectric ceramics have potential for applications in mobile and satellite communications systems at frequencies higher than 10GHz. The Ba$(Zn_{1/3}Ta_{2/3})O_3$ ceramics are known to have a high quality factor, a small temperature coefficient of the resonance frequency and a high dielectric constant. On the other hands, sintering at high temperature for extended time is required to obtain the ordered structure for high quality factor. In this study, the microwave dielectric properties of $ZrO_2$ and NiO-added Ba$(Zn_{1/3}Ta_{2/3})O_3$ ceramics prepared by solid-state reaction have been investigated. Adding $ZrO_2$ and NiO could effectively promote the densification even the case of decreasing the sintering time. At the surface of samples, secondary phase of Ba-Ta compounds was formed possibly due to the evaporation of ZnO, however, the interior of the samples remained as pure Ba$(Zn_{1/3}Ta_{2/3})O_3$. The samples sintered at $1600^{\circ}C$ for 2h exhibited 1:2 ordering of Zn and Ta cations. Excellent microwave dielectric properties of $Q{\cdot}f$(>96,000 GHz) and ${\varepsilon}_r$=30 has been obtained.

• 한국세라믹학회지
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• 제56권1호
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• pp.91-97
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• 2019

The effect of different Ni-containing additives on the sintering behavior and electric conductivity of the proton conducting electrolyte $BaCe_{0.35}Zr_{0.5}Y_{0.15}O_{3-{\delta}}$ (BCZY5) was investigated. Ni-doped, NiO-added, and $BaY_2NiO_5$(BYN)-added (all 4 mol%) BCZY5 samples were prepared by the solid state synthesis method and sintered at $1400^{\circ}C$ for 6 h. Among the three samples, the onset of densification was observed at the lowest temperature for NiO-added BCZY5, which is attributed to the formation of an intermediate phase at a low melting temperature. The BYN-added sample, where no consumption of the constitutional elements of the electrolyte was expected during sintering, exhibited the highest electrical conductivity whereas the doped sample had the lowest conductivity. The electrical conductivities at $500^{\circ}C$ under humid argon atmosphere were measured to be 2.0, 4.8, and $6.2mS{\cdot}cm^{-1}$ for Ni-doped and NiO- and BYN-added samples, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
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• pp.75-78
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• 2002

The dielectric properties for Ni electrode multilayer ceramic chip capacitor for Y5V has been studied with $(Ba_{0.93}Ca_{0.07})_m(Ti_{0.82}Zr_{0.18})O_2+MnO_2$ 0.2wt%, $Y_2O_3$ 0.18wt%, $SiO_2$ 0.15wt%, glass frit 1 wt% composition. The m ratio in the range of 1.006 ~ 1.012 have dielectric constant 9,500 ~ 14,500 and insulation resistance 390 ~ 460 $G{\Omega}$. Using the dielectrics, nikel electrode multilayer chip capacitor with Y5V, 104Z in EIA 0603 size specific capacitance were developed.

• 한국세라믹학회지
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• 제55권4호
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• pp.358-363
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• 2018

To improve the polarization property of cathodes, which is the main factor limiting the performance of protonic ceramic fuel cells (PCFCs), $K_2NiF_4-type$ $Pr_2NiO_{4+{\delta}}$, which is expected to exhibit a triple conducting property (proton, oxygen ion, and hole conductions) was applied to PCFCs and its properties were investigated. Low-temperature microwave heat-treatment was used to achieve both sufficient interface adhesion between the electrolyte and the cathode layers and suppression of the secondary phase formation due to migration of elements such as barium and cerium. Through this fabrication method, a high performance of $0.82W{\cdot}cm^{-2}$ and low ohmic resistance of $0.06{\Omega}{\cdot}cm^2$ were obtained in an $Ni-BaCe_{0.55}Zr_{0.3}Y_{0.15}O_{3-{\delta}}$ | $BaCe_{0.55}Zr_{0.3}Y_{0.15}O_{3-{\delta}}$ | $Pr_2NiO_{4+{\delta}}$ single cell at $650^{\circ}C$. This result verifies that the $K_2NiF_{4+{\delta}}-type$ cathode shows good chemical compatibility which, in turn, will make it a potent candidate as a PCFC cathode.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1997년도 한국재료학회 춘계학술발표회
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• pp.62-62
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• 1997

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 추계학술대회 논문집
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• pp.44-47
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• 1995

In this study, dielectric and piezoelectric properties of 0.4[0.1Bi(Ni$\_$1/2/Ti$\_$1/2/)O$_3$0.9Pb(Ni$\_$1/3/Nb$\_$2/3/)O$_3$]-0.6(PbZr$\_$y/Ti$\_$1-y/)O$_3$ceramics with Zr/Ti ratio were observed. As a results, structure of the ceramics with ZrO$_2$(y) 0.425 and 0.45 was MPB. Electromechanical coupling coefficients k$\_$p/, k$\_$31/ of the BN$\_$162/ specimen were 57.2%, 35.6% and piezoelectric constants d$\_$33/, d$\_$31/ were 720, 298[x10$\_$-12/C/N).