http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
CaO첨가$(Ba, Pb)O-Nd_2O_3-TiO_2$ 세라믹스의 고주파 유전특성
윤상옥,최환,김경용,Yoon, Sang-Ok,Choi, Whan,Kim, Kyung-Yong 한국세라믹학회 1993 한국세라믹학회지 Vol.30 No.2
Effects of CaO on microwave dielectric properties of (Ba, Pb)O-Nd2O3-TiO2 ceramic ystem were investigated. As the content of CaO increases, the sintered bulk density decreases due to the decrease of sinterability. However, with increasing the sintering tmperature, the relative dielectric constants increases. This has been attributed on the formation of the 2nd phase inclusion, TiO2(rutile). The Q values increase due to the compensation effect of Ca ions up to 1 wt%, and then decrease due to the interfacial relaxation effects. The temperature coefficient of resonance frequency increases to a positive direction with increasing the amounts of CaO.
윤상옥,김관수,조태현,심상흥,박종국,Yoon Sang-Ok,Kim Kwan-Soo,Jo Tae-Hyun,Shim Sang-Heung,Park Jong-Guk 한국전기전자재료학회 2006 전기전자재료학회논문지 Vol.19 No.6
$xCa(Li_{1/4}Nb_{3/4})O_{3}-(1-x)CaTiO_{3}$ ceramics were sintered under the presence of zinc-borosilicate(ZBS) glass and resultant microwave dielectric properties were investigated with a view to applying the composition to low-temperature co-fired ceramic(LTCC) technology. The addition of $5{\sim}15wt%$ ZBS glass ensured successful sintering below $900\;^{\circ}C$. In general, increased addition of ZBS glass increased sinterability but it decreased the quality factor($Q{\times}f_{0}$) significantly due to the formation of an excessive liquid and second phases. As for the addition of $CaTiO_3$, the dielectric constant(${\epsilon}_r$) and temperature coefficient of resonant frequency(${\tau}_f$) increased, while the quality factor($Q{\times}f_{0}$) did not show an apparent change. The sintered $0.9Ca(Li_{1/4}Nb_{3/4})O_{3}-0.1CaTiO_{3}$ specimen at $900\;^{\circ}C$ with 10 wt% ZBS glass demonstrated 39.6 in dielectric constant(${\epsilon}_r$), 4,400 in quality factor$(Q{\times}f_{0}),\;and\;-11ppm/^{\circ}C$ in temperature coefficient of resonant frequency(${\tau}_f$).
저온 소결용 xZnWO<sub>4</sub>-(1-x)TiO<sub>2</sub> 세라믹스의 소결 및 마이크로파 유전 특성
윤상옥,김관수,심상흥,박종국,Yoon, Sang-Ok,Kim, Kwan-Soo,Shim, Sang-Heung,Park, Jong-Guk 한국전기전자재료학회 2006 전기전자재료학회논문지 Vol.19 No.9
Sinterability and microwave dielectric properties of $xZWO_{4}-(1-x)TiO_{2}$ ceramic systems with zinc-borosilicate glass and $TiO_{2}$ contents for LTCC(Low Temperature Co-fired Ceramics) were investigated. The addition of $3{\sim}10\;wt%$ ZBS glass ensured the sinterability below $900^{\circ}C$. In general, increasing ZBS glass content seemed to enhance the sinterability, but the quality factor($Qxf_{0}$) significantly decreased due to the formation of an excessive liquid and second phases. As for the addition of $TiO_{2}$, the dielectric constant(${\varepsilon}_{r}$) and temperature coefficient of resonant frequency(${\tau}_{f}$) showed to increase, while the quality factor($Qxf_{0}$) did not show an apparent change. The composition of $0.7xZnWO_{4}-0.3TiO_{2}$ ceramics sintered at $900^{\circ}C$ with 5 wt% ZBS glass demonstrated 21.6 in dielectric constant(${\varepsilon}_{r}$), 14,800 in quality factor($Qxf_{0}$), and $+5\;ppm/^{\circ}C$ in temperature coefficient of resonant frequency(${\tau}_{f}$).
반도성 세라믹스에서 복소임퍼던스 공진법을 이용한 전기적 특성의 평가
윤상옥,정형진,윤기현 한국세라믹학회 1994 한국세라믹학회지 Vol.31 No.8
Electrical properties of each interfacial layers on semiconducting ceramics have been analized and evaluated by complex impedance resonance method as functions of ambient temperatures and applied voltages. From the analytical results, it can be observed that the interfacial layers in a semiconducting ceramics vary individually with the ambient temperature and then this influence the total properties. Also, it has been confirmed that the applied voltage on semiconducting ceramics affect mainly the electrode interface, and thus the resistance and capacitance decrease due to the variation of potential barrier layers.
윤상옥,정형진 한국세라믹학회 1987 한국세라믹학회지 Vol.24 No.3
The characteristics of cobalt oxide powders prepared by hot petroleum drying method from the cobalt acetate were evaluated by DTA/TGA, XRD, BET, SEM and density measurement. The cobalt oxide powder could be prepared by hot petroleum drying of the emulsion of cobalt acetate salt solution and the subsequent thermal decomposition of the acetate at 300$^{\circ}C$. As the concentration of the salt solution and the calcination temperature of the dried powder increased, the surface area of the synthesized powder decreased due to the particle growth, so that after sintering the density and grain size decreased. For the same concentration of the salt solution, the surface area and sinterability of the powder by hot petroleum drying increased in comparision with those by conventional drying.
$Pb_5Ge_3O_11$에 의한 반도성 $BaTiO_3$ 세라믹스의 저온소결성
윤상옥,정형진,윤기현 한국세라믹학회 1991 한국세라믹학회지 Vol.28 No.5
The effects of Pb5Ge3O11 on the sinterbility and lattice variation of the semiconducting 0.15 mol% Y2O3 doped BaTiO3 have been investigated as functions of additive contents (from 0.25 mol% to 2.5 mol%) and sintering temperatures (from 110$0^{\circ}C$ to 130$0^{\circ}C$). As the amount of Pb5Ge3O11 increases, the sinterbility of BaTiO3 increases abruptly at around 115$0^{\circ}C$. During the sintering, the most of Pb+2 ions in additives penetrate into BaTiO3 lattices and Ge+4 ions present at grain boundaries. Therefore the c lattice of the BaTiO3 increases largely and then the tetragonality increases due to the diffusion of the Pb+2 ions.
Lead-Borosilicate Glass계 LTCC용 유전체에 대한 고찰
윤상옥,오창용,김관수,조태현,심상흥,박종국,Yoon, Sang-Ok,Oh, Chang-Yong,Kim, Kwan-Soo,Jo, Tae-Hyun,Shim, Sang-Heung,Park, Jong-Guk 한국세라믹학회 2006 한국세라믹학회지 Vol.43 No.6
The effects of lead-borosilicate glass frits on the sintering behavior and microwave dielectric properties of ceramic-glass composites were investigated as functions of glass composition of glass addition ($10{\sim}50vol%$), softening point (Ts) of the glass, and sintering temperature of the composites ($500{\sim}900^{\circ}C$ for 2 h). The addition of 50 vol% glass ensured successful sintering below $900^{\circ}C$. Sintering characteristics of the composites were well described in terms of Ts. PbO addition in to the glass enhanced the reaction with $Al_{2}O_3$ to form liquid phase and $PbAl_{2}Si_{2}O_8$, which was responsible to lower Ts. Dielectric constant(${\epsilon}_r$), $Q{\times}f_0$ and temperature coefficient of resonant frequency (${\tau}_f$) of the composite with 50 vol% glass contents ($B_{2}O_{3}:PbO:SiO_{2}:CaO:Al_{2}O_3$ = 5:40:45:5:5) demonstrated 8.5, 6,000 GHz, $-70\;ppm/^{\circ}C$, respectively, which is applicable to substrate requiring a low dielectric constant. When the same glass composition was applied sinter $MgTiO_3\;and\;TiO_2,\;at\;900^{\circ}C$ (50 vol% glass in total), the properties were 23.8, 4,000 GHz, $-65ppm/^{\circ}C$ and 31.1, 2,500 GHz, $+80ppm/^{\circ}C$ respectively, which is applicable to filter requiring an intermidiate dielectric constant.