• Transactions of Materials Processing
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• v.21 no.4
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• pp.228-233
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• 2012

In this study, powder compaction of AZO (alumina doped zinc oxide) powder was performed with a MTS 810 test system using a cylindrical die having a diameter of 10mm. Pressure-density curves were measured based on the load cell and displacement of the punch. The AZO powder compacts with various densities were formed to investigate the mechanical properties such as fracture stress of the AZO powder as a function of the compact density. Two types of compression tests were conducted in order to estimate the fracture stress using different loading paths: a diameteral compression test and a uniaxial compression test. The pressure-density curves of the AZO powder were obtained and the fracture stress of the compacted powders with various densities was estimated. The results show that the compact pressure dramatically increases as the density increases. Based on the experimental results, calibration of the modified Drucker-Prager/Cap model of the AZO powder for use in FE simulations was developed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.1
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• pp.191-196
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• 2010

Aluminum doped zinc oxide (AZO) films have been prepared on Coming 7059 glass substrates by r.f. magnetron sputtering method. A powder target instead of a conventional sintered ceramic target was used in order to improve the utilization efficiency of the target and reduce the cost of the film deposition process. The influence of sputter pressure on the structural, electrical, and optical properties of AZO films were studied. The AZO films had hexagonal wurtzite structure with a preferred c-axis orientation, regardless of sputter pressure and target types. The crystallinity and degree of orientation was increased by increasing the sputter pressure. For higher sputtering pressures, a reduction of the resistivity was observed due to a increase on the mobility and the carrier concentration. The lowest resistivity of $6.5{\times}10^{-3}\;{\Omega}-cm$ and the average transmittance of 80% can be obtained for films deposited at 15 mTorr.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2001.11a
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• pp.97-98
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• 2001

Acid Orange 7과 Methyl Orange의 경우, UV 빛을 조사하고 $TiO_2$ powder를 투여하였을 때 120분 이내에 탈색이 완전히 이루어짐으로써 색도를 80% 이상 제거할 수 있었다. 광촉매량이 증가할수록 촉매표면적이 증가하여 광반응 속도의 증가를 가져오나, 과도한 촉매량의 투입은 오히려 UV 빛의 효과적인 투과를 방해함으로써 광반응 속도를 감소시킨 것으로 사료된다. 초기 pH는 반응 속도에 큰 영향을 미치지 못하는 것으로 나타났으며, Orange II는 Methyl Orange보다 초기 pH에 다소 큰 영향을 받았다. 초기 농도가 낮을수록 초기 반응 속도는 증가하여 염료 분해 속도가 빠름을 알 수 있었다.