• Journal of the Korean Ceramic Society
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• v.32 no.8
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• pp.931-937
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• 1995

AlN powder and whiskers were synthesized by direct nitridation of aluminum powder in pure nitrogen atmosphere. The nitridation reaction of aluminum powder was initiated by heating the sample to the ignition temperature and the reaction was finished in less than 3 minutes. AlN whisker-shaped morphology was observed predominantly when the sample was heated above 90$0^{\circ}C$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.04b
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• pp.3-6
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• 2009

Aluminum nitride (AIN) thin films were deposited on a polycrystalline 3C-SiC intermediate layer by a pulsed reactive magnetron sputtering system. Characteristics of the AIN/SiC heterostructures were investigated by field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The columnar structure of AIN thin films was observed by FE-SEM. The surface roughness of AlN films on the 3C-SiC buffer layer was measured using AFM. The XRD pattern of AlN films on SiC buffer layers was highly oriented at (002). Full width at half maximum (FWHM) of the rocking curve near (002) reflections was $1.3^{\circ}$. The infrared absorbance spectrum indicated that the residual stress of AIN thin films grown on SiC buffer layers was nearly negligible. The 3C-SiC intermediate layers are promising for the realization of nitride based electronic and mechanical devices.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1579-1582
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• 2011

Alumina particles wrapped in few-layer graphene sheets were prepared by calcining aluminum nitride powders under a mixed gas flow of carbon monoxide and argon. The graphene sheets were characterized by powder X-ray diffraction (XRD), Raman spectroscopy, electron energy loss spectroscopy, and high-resolution transmission electron microscopy. The few-layer graphene sheets, which wrapped around the alumina particles, did not exhibit any diffraction peaks in the XRD patterns but did show three characteristic bands (D, G, and 2D bands) in the Raman spectra. The dye-sensitized solar cell (DSSC) with the alumina particles wrapped in few-layer graphene sheets exhibited significantly improved overall energy-conversion efficiency, compared to conventional DSSC, due to longer electron lifetime.

• Journal of the Korean Ceramic Society
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• v.42 no.1
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• pp.16-21
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• 2005

The effect of additive composition, using AlN and $Er_{2}O_{3}$ as sintering additives, on the mechanical properties of liquid-phase-sintered, and subsequently annealed SiC ceramics was investigated. The microstructures developed were quantitatively analyzed by image analysis. The average thickness of SiC grains increased with increasing the $Er_{2}O_{3}/(AlN + Er_{2}O_{3})$ ratio in the additives whereas the aspect ratio decreased with increasing the ratio. The mechanical properties versus $Er_{2}O_{3}/(AlN + Er_{2}O_{3})$ ratio curve had a maximum; i.e., there was a small composition range at which optimum mechanical properties were realized. The best results were obtained when the ratio ranged from 0.4 to 0.6. The flexural strength and fracture toughness of the SiC ceramics were $550\~650\;MPa$ and $5.5\~6.5$ MPa${\cdot}m^{1/2}$, respectively.

• Journal of the Korean Society for Heat Treatment
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• v.23 no.6
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• pp.331-337
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• 2010

Aluminum nitride (AlN) thin films containing various amounts of Co content have been deposited by using a two-facing targets type sputtering (TFTS) system. The deposited films were also annealed successively and isothermally at different temperatures. Annealing treatment can control the physical properties as well as the microstructure of AlN films with Co particles. High magnetization and high resistivity are obtainable in AlN films containing dispersed Co particles. The coercivity of the films does not depend on annealing time, but it increases with increasing annealing temperature due to the increase of the grain size. A high saturation magnetization of 46 kG and resistivity of 2200 ${\mu}{\Omega}$-cm was obtained for AlN films containing 25 at% Co.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.2
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• pp.54-58
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• 2014

AlN (Aluminum Nitride) crystals were grown by a PVT (Physical Vapor Transport) method and were characterized to phases on the growth temperature. The crystals phase and morphology were analyzed using an optical stereo-microscope and the optimum temperature for the growing was determined. In this report, the characteristics of the AlN crystals grown at various temperatures were reported.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1563-1566
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• 2009

One-dimensional aluminum nitride (AlN) nanostructures were synthesized by calcining an Al(OH)(succinate) complex, which contained a very small amount of iron as a catalyst, under a mixed gas flow of nitrogen and CO (1 vol%). The complex decomposed into a homogeneous mixture of alumina and carbon at the molecular level, resulting in the lowering of the formation temperature of the AlN nanostructures. The morphology of the nanostructures such as nanocone, nanoneedle, nanowire, and nanobamboo was controlled by varying the reaction conditions, including the reaction atmosphere, reaction temperature, duration time, and ramping rate. Iron droplets were observed on the tips of the AlN nanostructures, strongly supporting that the nanostructures grow through the vapor-liquid-solid mechanism. The variation in the morphology of the nanostructures was well explained in terms of the relationship between the diffusion rate of AlN vapor into the iron droplets and the growth rate of the nanostructures.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.346-347
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• 2007

Aluminum nitride (AlN) thin films were deposited on Polycrystalline (poly) 3C-SiC buffer layers using pulsed reactive magnetron sputtering. Characteristics of AlN films were investigated experimentally by means of FE-SEM, X-ray diffraction, and FT-IR, respectively. As a result, highly (002) oriented AlN thin films with almost free residual stress were achieved using 3C-SiC buffer layers. Therefore, AlN thin films grown on 3C-SiC buffer layers can be used for various piezoelectric fields and M/NEMS applications.

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.11a
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• pp.153-153
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• 1999

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1998.10b
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• pp.12-13
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• 1998