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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 6, Issue 4 - Nov 1996
Volume 6, Issue 3 - Aug 1996
Volume 6, Issue 2 - May 1996
Volume 6, Issue 1 - Mar 1996
Selecting the target year
Electrical and optical properties of ZnO:Al thin films prepared by reactive sputtering method
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 480~492
AZO (Aluminum doped Zinc Oxide) transparent conducting thin films were fabricated by reactive DC mangnetron sputtering method using zinc target containing 2 wt% of Al. Transition range with optimum transmittance and conductivity was obtained by contrlling partial pressure of reactive oxygen gas. Sputtering condition for this transition range could be kept stable by regulating the target voltage. According to XRD analysis, there was only one peak for (002) plane in AZO films and the films deposited in transition range.
Effect of heat treatment on the electrical and optical properties of ZnO : Al thin films prepared by reactive magnetron sputtering method
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 493~500
AZO transparent conducting thin films were fabricated by reactive DC magnetron sputtering method using Zn metla target containing 2 wt% of Al, and electrical and optical properties were investigated after heattreatment. Electrical resistivity was reduced 50% and had reached
by heat treatment. In the case of oxide AZO films, the resistivity of
was also decreased to
after heat treatment. The optical transmittance of AZO films deposited in the transition range was increased from 59.4 % to 77.4 % by
, 30 min heat treatment.
Powder synthesis and morphology changes of strontium barium niobate by molten salt method
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 501~508
Strontium barium niobate powders were prepared by NaCl-KCl molten salt, and reaction process and morphology change of strontium barium niobate were investigated as a function of reaction temperature, time, and amount of molten salt. With increasing the reaction temperature and time, the reacted fraction was increased and the morphology of powder was changed from lumpy shape into meedle-like shape. With increasing the amount of molten salt, reacted fraction was increased rapidly, but the morphology of powder was changed from needle-like shape into spherical shape. Strontium barium niobate powder, over 90 % in fraction reacted, was obtained from the reaction conditions at
for small flux ratio (=1) and at
for large flux ratio (=4).
Synthesis of ultrafine calcium carbonate powders from high concentrated calcium hydroxide solution
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 509~520
Ultrafine calcim carbonate powders with the size of
and the calcite phase were synthesized by the nozzle spouting method, which could be only obtained when high calcium ion concentration within slurry was maintained at the beginning of the reaction. But, in the regions of low
concentration (0.5~1.0 wt%) or high
concentration (<3.0 wt%), synthesized calcium carbonate powder was shown the large particle size with agglomeration. To obtain ultrafine calcium carbonate powder in this region, the methods of slurry circuation and
gas supply were changed during reaction. Resultly, it was possible to synthesize ultrafine particles (
)in the regions of low
) and high
), which can not be obtained the fine calcium carbonate powder still now.
Preparation process of functional particles : I. Preparation of microcapsule by spray drying
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 521~531
Inorganic and inorganic/organic microcapsules were prepared by spray drying.
and clay were used as the core and colloidal silica as the shell for the inoroganic microcapsules. Forthe inorganic/organic microcapsules were used the inorganic microcapsule which were mentioned above (core) and ethyl cellulose (shell). To characterize the prepared microcapsule for the practical use, the homogenity of surface and pore volume are the dominent factors. At the volume ratio of 0.3/0.7 of core/shell, the spherical and homogeneous surfaces of inorganic microcapsule could be synthesized. In the case of inorganic/organic microcapsules, the weitht ratio was 0.76/0.24. The pore volume of inorganic/organic microcapsules decreases more than that of inorganic microcapsule. The more the amount of shell (ethyl cellulose) in inorganic/organic microcapsules increases, the more the coating became homogeneous and the pore volume decreased.
Single crystals growth and properties of
doped with MgO or ZnO : (II) The electrical and optical properties
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 532~542
The electrical and optical properties of the annealed
single crystal with congruently melting composition and MgO or ZnO doped
single crystal grown by the FZ method. The electrical and optical properties such as electrical conductivity, dielectric constant (Curie temperature), electro-mechanical coupling factor, optical transmittance and refractive indices of the grown crystals were measured and the nonlinear refractive indices of the grown crystals were calculated theoretically. The doping effects of MgO and ZnO were investigated by comparing the electrical and optical properties of the undoped
single crystal and those of the
single crystals doped with MgO or ZnO.
The specimen preparation for the high energy electron diffraction and reflection electron microscopy observation
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 543~551
The use of reflection high energy electron diffraction and reflection electron microscopy technique has been increased with increasing number of studieds on surfaces of single crystals and epitaxial growth layers. Here, the speciment preparation techniques are summerized for these two techniques which are not so polular in the country. The panoramic reflection high energy electron diffraction maps have been completed and an example of Pt(111) surface was demonstrated.
Microstructural development of
nanocomposites during hot pressing
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 552~557
Microstructural development of
/20 vol% SiC nanocomposites doped 2 wt%
and 6 wt%
as sintering additives were analyzed by sintering interruption. Density of samples was significantly increased between
, and near full density was achieved at
. Transformation rate from
was increased at
, and then elongated matrix grains were appeared. Small size SiC particles had suppressive effect on densification rate and transformation of
Change of high temperature strength of
nanocomposites with sintering additives
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 558~563
Fracture strength of
vol% SiC nanocomposites with fifferent sintering additives was measured. Strength of nanocomposites with 6 wt%
and 2 wt%
as sintering additives was higher at room temperature but significant strength degradation at elevated temperature was occured due to the softening of grain boundary phase. Fracture strength of 8 wt%
doped sample was higher than that of
added sample at
. The retention of high temperature strength in 8 wt%
doped sample can be attributed to high softening temperature and crystallization of grain boundary glassy phase.
On the study of two luminescence band structfue from ambient air aged porous silicon
Sung-Sik Chang ; Akira Sakai ;
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 564~570
We have observed the red and blue luminescence from porous silicon (PS) without any rapid thermal oxidation. Aged porous silicon specimens prepared in dilute HF concentration, especially for the short duration of etching, display the increase of the blue band. The measured luminescence decay time at room temperature exhibits a decay time of about 100 ps and shows appreciably faster decay time than that of 20 K. No photoluminescence (PL) peak maximum shift is observed for the blue PL band at 77 K. However, the red PL band shows the blue shift and displays yellow luminescence at 77 K. The origin of red luminescence has some properties related to Si crystallites, whereas blue luminescence seems to be associated other than Si crystallites.
A study on the characterization of electrode at graphite materials by impedance spectroscopy
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 571~583
The electrochemical behavior on electrographite and graphite foil electrode with porous surface in 0.5 M
solution with 1 mM
have been characterized by impedance spectroscopy. In cyclic voltammograms, relative high current according to structure of porous surface for graphite materials was represented, and indicated hgih double layer capacitance on graphite foil. The faraday-impedance and the change of impedance spectrum on both graphite materials were not remarkable during polarization by reaction of field transport. Chemical adsorption was represented on electrographite and was depended highly at anodic polarization.
Crystallization and high purification of aluminium chloride hexahydrate from kaolin leaching solution
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 584~594
For the separation and purification of aluminium chloride hexahydrate crystals from kaolin leaching solution the effects of crystallization conditions, such as crystallization temperature, concentration of aluminium chloride concentration in the leaching solutin and gas flow rate of HCl into the leaching solution, on purity of the aluminium chloride hexahydrate crystals were investigated. The supersaturation level of aluminium chloride in the leaching solution gave great influence on the purity of the crystals. When supersaturated concentration of the aluminium chloride in the leaching solution was generated in low level, the aluminium chloride hexahydrate crystals were produced with high purity ; that is, the crystals hving a low Fe-ion concentration. The supersaturation level of aluminium chloride in the leaching solution was mainly determined by crystallization temperature, concentrations of aluminium chloride and hydrochloric acid in the solution. However, in spite of changes of the above crystallization coditions, a needle shape morphology of aluminium chloride hexahydrate crystals did not modified. To measure hydrochloric acid concentration in the kaolin leaching solution, we applied the oxalate titration method, which was suggested by shank  and it was prove that this method could titrate hydrochloroic acid concentration in multi-component ionic solution such as kaolin leaching solution.
The behaviour of the internal bubbles in
crystals during the annealing process
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 595~599
The behaviour of the internal bubbles present in
crystals was characterized crystallographically using a variety of the mircroscopical technique. The bubble defects were found to be aligned on the characteristic planes and directions depending on the crystals structure of the
. The AFM analysis revealed that these behaviors are related to the S-surface formation by the negative grain growth mechanism.
A study on synthesis of
for asecondary battery with various
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 600~608
Specific structural properties of Li intercalation reaction into the spinel relatedmanganese dioxide,
, are investigated by X-ray diffractional and electrochemical studies of Li/1M
-propylene carbonate solution/
cell. The effect of the chemical composition and the reaction temperature on electrochemical parameter of
are studied by the phenomena of phase-transition, analysis of crystal lattice, fine structure, and thermal analysis. Treatment of the spinel
with aqueous acid was found to result in conversiton of
to nearly pure
, as evidenced by a reduction in the lattice constant
from 8.255 to
. At a composition range of
the reduction proceeded in a homogeneous phase, which was characterized by a constant voltage of 3.9~3.7 V together with a lattice constant of
Study on the reaction crystallization of silver chloride in Rushton type semi-batch reactor
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 609~619
Experimental study on effects of factors on the reaction crystallization of silver chloride in rushton type reactor. The size and size distributions of the silver chloride crystals were observed to be markedly affected by the agitation speed of solution, and feeding rate, feeding mode and concentration of reactants. From experimental data it was inferred that in the reaction crystallization of silver chloride the supersaturation level of silver chloride and concentration of excess ions in the solution, and mass transfer rate around the crystals were implicitly interrelated with factors and directly affected on the crystal nucleation and grwoth processes. However, the morphology of the silver chloride crystal was not changed by factors.
Defect structure of lithium niobate single crystals grown by the Czochralski method
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 620~626
single crystals were grown using a self-designed radio-frequency heating Czochralski crystal grower. Congruently melting composition was used and the optimum growth conditions were established. The compensated power control method was very effective to control the outer diameter of the crystal ingots within
. Scanning electron microscopy was performed to characterize the effect of the
ions on the formation of the ferroelectric domain in
The treatment of coal fly ash for recycling as ceramic raw materials : II. The effects of sampling condition and pH treatment in elutriation
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 627~639
Charateristics of Ansan and Boryong coal fly ashes collected at different seasons were investigated for the recycling them as ceramic raw materials. The effect of pH treatment on the classification of Ansan coal fly ashes by elutriation was discussed. Charateristics of ansan and boryong coal fly ashes were not significantly changed with power plants and seasons. major crystalline phases were mullite and quartz. These results suggested that coal fly ashes cab be used as raw materials instead of clay minerals. However, particle size distribution was very broad from a few
. Especially, ansan coal fly ashes have various morphologies. Therefore, coal fly ashes should be classified before using as raw materials. Because of higher dispersion by pH treatment, spherical cenospheres were mainly collected in the 4th step and particle size distribusion was also decreased by elutriation for the ansan coal fly ashes. The specific surface area of the sample collected in the 4th step was
which was smaller than that of not treated Ansan coal fly ashes.
Study on the whitening phenomenon on inside of glass bottle by surface analysis methods
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 640~647
It has been found that an white precipitates at the inside surface is a common characteristics of soda-lime-silica glasses which have not undergone special surface treatments during hot weather season. In this study, the white deposits were examed using by solution method, surface analysis etc., and the dependence of weathering on the atmospheric condition was also investigated. As a results, the white precipitates on the glass surface was discorved as carbonates like
. Coming to atmosphere-dependence, it was shown that the glass made and stored at sea shore province had 3 times much severe weathering than that at land province.
Study on the surface reactions of carbon and graphite electrodes in sulfuric acid solution
Journal of the Korean Crystal Growth and Crystal Technology, volume 6, issue 4, 1996, Pages 648~662
Electrode surface reaction on glassy carbon and synthesized graphite (PVDF mixed graphite) in sulfuric acid solution is investigated by impedance spectroscopy at cyclic polarization. The redox peak, which may be due to the change of chemical adsorped functional group on electrode surface or oxidation and reduction of oxygen, is represented on glassy carbon and graphite electrode in potentio-dynamic current curve. The oxidation and reduction of these surface functional group on glassy carbon and PVDF mixed graphite have a major affect on the impedance spectrum and Faraday impedance parameter at cyclic polarization.