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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Crystal Growth and Crystal Technology
Journal Basic Information
Journal DOI :
The Korea Association of Crystal Growth
Editor in Chief :
Volume & Issues
Volume 15, Issue 6 - Dec 2005
Volume 15, Issue 5 - Oct 2005
Volume 15, Issue 4 - Aug 2005
Volume 15, Issue 3 - Jun 2005
Volume 15, Issue 2 - Apr 2005
Volume 15, Issue 1 - Feb 2005
Selecting the target year
A study on the growth mechanism of rutile single crystal by skull melting method and conditions of RF generator
Seok jeong-Won ; Choi Jong-Koen ;
Journal of the Korean Crystal Growth and Crystal Technology, volume 15, issue 5, 2005, Pages 175~181
Ingots of rutile single crystals were grown by the skull melting method, and their characteristics were compared in terms of melt-dwelling time for each melt. The method is based on direct inductive heating of an electrically conducted melt by an alternating RF field, and the heating is performed by absorption of RF energy.
is an insulator at room temperature but its electric conductivity increases elevated temperature. Therefore, titanium metal ring(outside diameter : 6cm, inside diameter : 4cm, thickness 0.2cm) was embedded into
, powder (anatase phase, CERAC, 3N) for initial RF induction heating. Important factors of the skull melting method are electric resistivity of materials at their melting point, working frequency of RF generator and cold crucible size. In this study, electric resitivity of
at its melting point was estimated by compairing the electric resitivities of alumina and zirconia. Inner diameter and height of the cold crucible was 11 and 14cm, respectively, which were determined by considering of the Penetration depth
and the frequency of RF generator.
A study on the identification of ruby and garnet by optical method
Hwang Ji-Ho ; Choi Jong-Koen ;
Journal of the Korean Crystal Growth and Crystal Technology, volume 15, issue 5, 2005, Pages 182~187
The FT-IR absorption spectrum by the lattice vibrations of ruby and garnet obtained from FT-IR shows quite different characteristics. By the UV-VIS spectroscopy it was found that the ruby has two transmission bands in red and blue region, while garnet has only one transmission band in red region. The color filter to distinguish ruby from garnet was developed and named HWANG JI HO filter. Through the HWANG JI HO filter, ruby was shown in blue color and garnet was shown in dark red color because of the only the blue region transmittance of the filter. Other red stones, such as spinel, tourmaline were shown in dark red color like as garnet. The ruby could be recognized easily from the red stone.
Crystal growth and pinning enhancement of directionally melt-textured
oxides in air
Kim So-Jung ;
Journal of the Korean Crystal Growth and Crystal Technology, volume 15, issue 5, 2005, Pages 188~192
additive were systematically investigated by the zone melt growth process in air. Cylindrical green rods of (YNS)-123 oxides were fabricated by cold isostatic pressing (CIP) method using rubber mould. A sample prepared by this method showed well-textured microstructure, and
nonsuperconducting inclusions were uniformly dispersed in large
[(YNS)123] superconducting matrix. In this study, optimum melting temperature and growth rate were
and 3 mm/hr, respectively. The directionally melt-textured (YNS)-123 sample with
additive showed an onset critical temperature
and sharp superconducting transition.
Synthesis of CuO from organic-inorganic hybrid
Huh Young-Duk ; Kweon Seok-Soon ; Kuk Won-Kwen ;
Journal of the Korean Crystal Growth and Crystal Technology, volume 15, issue 5, 2005, Pages 193~197
CuO has been synthesized using the layered organic-inorganic hybrids,
as precursor. The simple thermal decomposition of
is used without any external organic templates. This method provides large-scale production at a low cost of the single-crystalline CuO particles. The morphology of CuO aggregated particles is strongly dependent on structure of the precursor.
Control the growth direction of carbon nanofibers under direct current bias voltage applied microwave plasma enhanced chemical vapor deposition system
Kim Sung-Hoon ;
Journal of the Korean Crystal Growth and Crystal Technology, volume 15, issue 5, 2005, Pages 198~201
Carbon nanofibers were formed on silicon substrate which was applied by negative direct current (DC) bias voltage using microwave plasma-enhanced chemical vapor deposition method. Formation of carbon nanofibers were varied according to the variation of the applied bias voltage. At -250 V, we found that the growth direction of carbon nanofibers followed the applied direction of the bias voltage. Based on these results, we suggest one of the possible techniques to control the growth direction of the carbon nanofibers.
Effects of viscosities of slip on slip casting and properties of sintered bodies of cordierite
Baik Yong-Hyuck ; Chang Pok-Kie ; Kwak Hyo-Sup ;
Journal of the Korean Crystal Growth and Crystal Technology, volume 15, issue 5, 2005, Pages 202~207
We have investigated the relationship between a viscosity of the slip prepared from kaolin, quartz,
, etc and its influence on the speed of slip casting and the microsturcture of a sintered body. The speed of slip casting decreases as a viscosity of a slip decreases. The optimized viscosity range of a slip was found to be around
. By careful controlling a viscosity of slip, homogeneous microstructure of outer surface layers, inner surface layers, intermediate layers, and inside layers were obtained by casting process. The specimen sintered at
consists of a cordierite crystalline phase only as a constituent mineral.
The mechanism of black core formation
Park Jiyun ; Kim Yootaek ; Lee Ki-Gang ; Kang Seunggu ; Kim Jung-Hwan ;
Journal of the Korean Crystal Growth and Crystal Technology, volume 15, issue 5, 2005, Pages 208~215
The 10mm diameter aggregates made of clay, carbon and
were prepared to investigate the mechanism of black core formation. The specific gravity, absorption rate, percent of black core area, fracture strength, total Fe analysis, and XRF were measured at various compositions, sintering temperatures, sintering times, sintering atmospheres, and sintering methods. Small addition of
did not affect physical properties of the aggregates; however, the percent of black core area increased with increasing carbon contents and increasing sintering temperature. Specific gravity of the aggregates decreased and the water absorption ratio increased with increasing percent of black core area. The aggregates sintered at oxidation atmosphere showed clear border between shell and black core area. Hence, the aggregates sintered at reduction atmosphere showed only black core area in the cross-section of the aggregates. The specific gravity of the aggregates sintered at reduction atmosphere increased with increasing carbon contents and that was the lowest of all comparing other aggregates sintered at different atmospheres. Adsorption rate increased with increasing carbon contents at all atmospheres. The fast sintered aggregates showed lower specific gravity, higher absorption rate, and more black core area than the normally sintered aggregates. It was turned out that the aggregates having more black core area showed higher fracture strength than that of aggregates with no black core area. From the total Fe analysis, the concentration of Fe and FeO was higher at black core area than at shell. Because the concentration of
in the shell was higher than other area, the color of the shell appeared red. It was also turned out from the XRF analysis that carbon was exist only at black core area.