• 제목/요약/키워드: Nb-Si-B

검색결과 144건 처리시간 0.028초

Crystalline Behavior and Microstructure Analysis in Fe73.28Si13.43B8.72Cu0.94Nb3.63 Alloy

  • Oh, Young Hwa;Kim, Yoon Bae;Seok, Hyun Kwang;Kim, Young-Woon
    • Applied Microscopy
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    • 제47권1호
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    • pp.50-54
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    • 2017

  • The microstructure, the crystallization behavior, and magnetic properties of FeSi-based soft magnetic alloys (FINEMET) were investigated using transmission electron microscopy, X-ray diffraction, and coercive force measurements. The amorphous $Fe_{73.28}Si_{13.43}B_{8.72}Cu_{0.94}Nb_{3.63}$ alloys particles, prepared in $10^{-4}$ torr by gas atomization process, were heat treated at $530^{\circ}C$, $600^{\circ}C$, and $670^{\circ}C$ for 1 hour in a vacuum of $10^{-2}$ torr. Nanocrystalline Fe precipitation was first formed followed by the grain growth. Phase formation and crystallite sizes was compared linked to its magnetic behavior, which showed that excellent soft magnetic property can directly be correlated with its microstructure.

  • https://doi.org/10.9729/AM.2017.47.1.50 인용 PDF KSCI

저온 소결제 첨가에 의한 LiNb3O8-TiO2계 세라믹스의 마이크로파 유전 특성 (Microwave Dielectric Properties of the LiNb3O8-TiO2 Ceramic System with the Addition of Low Firing Agents)

  • 최명호;김남철
    • 한국전기전자재료학회논문지
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    • 제21권6호
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    • pp.517-523
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    • 2008

  • The microwave dielectric properties of $LiNb_3O_8-TiO_2$ based ceramics with low firing agents, CuO, $Bi_2O_3$, $B_2O_3$, $SiO_2$, $TiO_2$, were investigated to improve the sintering condition for the LTCC system. According to the X-ray diffraction and SEM, the ceramics of $LiNb_3O_8-TiO_2$ with low firing agents showed no significant second phases within a range of experiments, and fine microstructures. By adding the low firing agents, the sintering temperature decreased from $1200^{\circ}C$ to $925^{\circ}C$. Based on the results of electrical measurements, the $LiNb_3O_8-TiO_2$ ceramics showed a promising microwave dielectric properties for LTCC applications, those are ${\varepsilon}_r$ (dielectric constant) = 44, Q f (quality factor) = 18000, and ${\tau}_f$ (the temperature coefficient of resonant frequency) = $-1.5\;ppm/^{\circ}C$.

  • https://doi.org/10.4313/JKEM.2008.21.6.517 인용 PDF KSCI

Zn-B-O 글라스 첨가에 의한 Ca[(Li1/3Nb2/3)0.2Ti0.8]O3-δ 세라믹스의 마이크로파 유전특성 (Microwave Dielectric Properties of Ca[(Li1/3Nb2/3)0.2Ti0.8]O3-δ Ceramics with Addition of Zn-B-O Glass Systems)

  • 인치승;김시연;여동훈;신효순;남산
    • 한국전기전자재료학회논문지
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    • 제29권12호
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    • pp.781-785
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    • 2016

  • With trend of the miniaturization and the high-functionalizing of mobile communication system, low-loss microwave dielectric materials are widely used for high frequency communication components. These dielectric materials should be co-sintered with highly electric-conducting metal such as silver or copper for high-frequency and thick film process application. Sintering temperature of $Ca(Li_{1/3}Nd_{2/3})_{0.2}Ti_{0.8}]O_{3-{\delta}}$, which has excellent dielectric properties such as ${\varepsilon}_r$ above 40, quality factor ($Q{\cdot}f_0$) above 16,000 GHz, and TCF (temperature coefficient of resonant frequency) of $-20{\sim}-10ppm/^{\circ}C$, is reported as high as $1,175^{\circ}C$, so it could not be co-sintered with silver or copper. Therefore in this study, low-temperature melting glasses of Zn-B-O and Zn-B-Si-O systems were added to $Ca[(Li_{1/3}Nb_{2/3})_{0.8}Ti_{0.2}]O_{3-{\delta}}$ to lower its sintering temperature under $900^{\circ}C$ without losing excellency of dielectric properties. With 15 weight % of Zn-B-Si-O glass and sintered at $875^{\circ}C$, specimen showed density of $4.11g/cm^3$, ${\varepsilon}_r$ of 40.1, $Q{\cdot}f_0$ of 4,869 GHz, and TCF of $-5.9ppm/^{\circ}C$. With 15 weight % of Zn-B-O glass and sintered at $875^{\circ}C$, specimen showed density of $4.14g/cm^3$, ${\varepsilon}_r$ of 40.4, $Q{\cdot}f_0$ of 7,059 GHz, and TCF of $-0.92ppm/^{\circ}C$.

  • https://doi.org/10.4313/JKEM.2016.29.12.781 인용 PDF KSCI

첨가제(Y, Nb)에 따른 PTCR $BaTiO_3$계 세라믹스의 결정구조 해석과 상전이 특성 (Phase transition and crystal structure analysis of PTCR $BaTiO_3$ ceramics with dopants (Y, Nb))

  • 차용원;원승신;백종후;이희수;엄우식;송준광;이인식;정훈택
    • 한국결정성장학회지
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    • 제7권2호
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    • pp.253-258
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    • 1997

  • 반도체화 첨가제인 $Y_2O_3$와 $Nb_2O_5$ 첨가랑 변화에 따른 PTCR $BaTiO_3$ 세라믹스의 결정구조 해석과 상전이 특성을 연구하기 위하여 ($Ba_{0.85}Ca_{0.15})TiO_3$ ＋ X m/o $Nb_2O_5$(Y m/o $Y_2O_3$) ＋ 0.08 w/o $Mn(NO_3)_2$ㆍ$6H_2O$ ＋ 0.25 w/o $SiO_2$ 계에서 X는 0.1 ~ 0.4로 Y는 0.2 ~ 0.4로 각각 변화시켜 실험을 수행하였다. $Nb_2O_5$의 첨가시 B-site 치환에 따라서 격자상수가 선형적으로 변화하다가 0.3 mol% 이상 치환할 경우 c 축의 격자상수가 급격히 감소함을 알 수 있었다. 이는 octahedron distortion둥의 원인으로 판단되며, 이러한 격자상수 변화는 상전이 온도 결과와도 잘 일치함을 확인할 수 있었다. 또한 $Y_2O_3$ 첨가의 경우 0.3 mol%가지는 A, B-site를 각각 치환하며 그 이상부터는 A-site 이온을 주로 치환하는 것을 격자상수 변화와 상전이 온도결과를 통해 알 수 있었으며, Rietveld 해석결과 $Y^{3+}$가 A-site 치환시 $Ba^{2＋}$와 $Ca^{2＋}$를 같은 비율로 치환한다는 것을 알 수 있었다.

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