• The Korean Journal of Ceramics
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• 제6권2호
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• pp.100-102
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• 2000

Co fine particles were dispersed in Au metal and $AlO_x$ amorphous matrices by vacuum evaporation and rf-sputtering, respectively, thus forming granular composite films having chemical compositions of $Co_{0.59}-Au_{0.41}$ and $Co_{0.52}/(AlO_x$)_{0.48}$. The films were annealed at 200~$500^{\circ}C$ to increase the size of the Co particles, from 30$\AA$ to 180$\AA$ in the Au matrix and 40$\AA$ to 180$\AA$ in the $AlO_x$ matrix, as revealed by X-ray diffraction analysis. The Co metal in as-deposited films have saturation magnetization equivalent to that of bulk Co, which is unchanged by the annealing, showing that the Co metal is not oxidized by the annealing. Magneto-optical Kerr rotation measured at $\lambda$=400-900nm for the $Co_{0.59}-Au_{0.41}$ film as deposited is larger than that calculated for the composition. The rotation increases as the film is annealed at $200^{\circ}C$ and $300^{\circ}C$, approaching to that of bulk Co. The Kerr rotation for the $Co_{0.52}-(AlO_x)_{0.48}$ film as deposited is smaller than that calculated for the composition based on Bruggeman effective medium theory. However, the rotation increases much, exceeding the rotation of the bulk Co as annealed at $300^{\circ}C$ and $400^{\circ}C$. As a possible origin of the marked magneto-optical enhancement a weak localization of light in granular structure is suggested.

• 한국포장학회지
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• 제5권1호
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• pp.30-36
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• 1999

1. 슬라이스 치즈용 복합필름의 두께는 일부 단체필름의 두께를 알수없어 총 두께로 나타냈음을 전제로 한다. K/PET 필름은 종횡 $9{\sim}20kg/mm^2$ 범위로, 일반 범용플라스틱 필름(PE, PP등)과 비교해보면 강도가 우수하다. 또 겉 포장용의 경우 $61.6{\mu}PVDC/PE/Al-vac/CPS,\;96.9{\mu}PE/PVDC/PE,\;79.3{\mu}PET/PVDC/L-LDPE,\;72.2{\mu}PET/PVDC/PE/Al-vac/PE$ 복합필름도 종횡 $4{\sim}10kg/15mm$범위로 외부로부터 보호하는데 매우 우수하다. 2. 치즈의 투습도에서 $40{\mu}PVDC$나 $15{\mu}K/PET$필름은 대략 $10g/m^2/24hr$정도로 습기 차단성이 일반 범용플라스틱 필름과 비교해보면 매우 우수하다. 또 겉포장용 복합필름으로 $61.6{\mu}PVOC/PE/Al-vac/CSP{\cdot}4.91<96.9{\mu}PE/PVDC/PE$ 와 $79.3{\mu}PET/PVDC/L-LDPE$ 약 $3.8<72.2{\mu}PET/PVDC/PE/Al-vac/PE\;0.41g/m^2{\cdot}24hr$로서 모두 차단성이 우수 하지만 특히 $72.2{\mu}PET/PVDC/PE/Al-vac/PE$ 필름이 가장 우수하므로 장기저장시 사용이 좋을 것으로 사료된다. 3. 치즈의 기체투과도에서 1) 산소투과도는 PVDC 필름은 $130cc/m^2{\cdot}24hr{\cdot}atm$로 K/PET 필름의 $19.9cc/m^2{\cdot}24hr{\cdot}atm$에 비해 약 6.5배로 가급적 K/PET필름의 사용이 요망된다. 그리고 겉포장용으로 $61.6{\mu}PVDC/PE/Al-vac/CPS\;25.3>96.9{\mu}PE/PVDC/PE\;15.3>79.3{\mu}PET/PVDC/L-LDPE\;13.4>72.2{\mu}PET/PVDC/Al-vac/PE\;1.81cc/m^2.24hr{\cdot}atm$ 복합필름에서 PET/PVDC/Al-vac/PE필름은 장기저장시 사용이 좋을 것으로 사료된다. 2) 질소가스 및 탄산가스투과도 각각 $61.6{\mu}PVDC/PE/Al-vac/CPS\;12.5,\;59.8>96.9{\mu}PE/PVDC/PE\;7.1,\;42.0>79.3{\mu}ET/PVDC/L-LDPE\;6.4,\;34.2>72.2{\mu}PET/PVDC/PE/Al-vac/PE\;0.74,\;4.2cc/m^2.24hr{\cdot}atm$으로 가장 우수한 PET/PVDC/PE/Al-vac/PE 복합필름이 장기저장용으로 이용이 좋을 것으로 사료된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.281-281
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• 2007

Low Temperature Co-fired Ceramic (LTCC) technology has been used in electronic device for various functions. LTCC technology is to fire dielectric ceramic and a conductive electrode such as Ag or Cu thick film below the temperature of $900^{\circ}C$ simultaneously. The glass-ceramic has been widely used for LTCC materials due to its low sintering temperature, high mechanical properties and low dielectric constants. To obtain the high strength, addition of filler, the microstructure should have various crystals and low pores in a composite. In this study, two glass frits were mixed with different alumina size(0.5, 2, 3.7um) and sintered at the range of $850{\sim}950^{\circ}C$. The microstructure, crystal phases, thermal and mechanical properties of the composites were investigated using FE-SEM, XRD, TG-DTA, Dilatomer. When the particle size of $Al_2O_3$ filler increased, the starting temperatures for the densification of the sintered bodies, onset point of crystallization, peak crystallization temperature in the glass-ceramic composites decreased gradually. After sintered at $900^{\circ}C$, the glass frits were crystallized as $CaAl_2Si_2O_8\;and\;CaMgSi_2O_6$. The purpose of our study is to understand the relationship between the $Al_2O_3$ particle size and thermal properties in composites.