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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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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 8, Issue 4 - Aug 1998
Volume 8, Issue 3 - Jun 1998
Volume 8, Issue 2 - Apr 1998
Volume 8, Issue 1 - Feb 1998
Selecting the target year
and Fe doped-LiTaO3 single crystal as holographic storage material
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 193~204
The single crystal of the
has large electro-optic effects, so it is applied to optical switch, acousto-optic deflector, and optical memory device as hologram using photorefractive effect. In this study, optic-grade undoped
single crystals were grown by the Czochralski method and optical transmission and absorption spectrums were measured in the wavelength of UV-VIS range. The curie temperature was determined with DSC and by measuring capacitance for the grown undoped crystal and ceramic powder samples of various Li/Ta ratio. In case of having a 48.6 mol%
as a starting Li/Ta ratio, the results of concentration variations were below 0.01 mol%
all over the crystal, so it was confirmed that
single crystals were grown under congruent melting composition having optical homogeneity. The curie temperature of the Fe:
crystal was increased with increased with increased doped Fe concentrations;by the ratio of
increase per Fe 0.1 wt%. Also, the optical transmittance was about 78 %, which was sufficient for optical device.
Growth, structure and SHG properties of Li, Mo-containing huntite-borates
K. Shimamura ; V.l. Chani ; T. Fukuda ;
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 205~210
containing huntite borates
were grown by spontaneous crystallization. All crystal show only the huntite-borate phase detected by X-ray powder diffraction analysis. On the basis of the data of the composition analysis, the occupation mechanism of each cation in the huntite structure has been discussed.
shows a six times higher intensity of the green light SHG detected by the powder technique than
A study on the growth and characteristics of
single crystal thin film by hot wall epitaxy
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 211~220
The stochiometric composition of
polycrystal source materials for the single crystal thin films were prepared from horizontal furnace. From the extrapolation method of X-ray diffraction patterns, it was found that the polycrystal
has tetragonal structure of which lattice constant
single crystal thin film was deposited on throughly etched GaAs(100) substrate from mixed crystal
by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were
respectively, and the growth rate of the single crystal thin films was about 0.5
/h. The crystallinity of the grown single crystal thin films was investigated by the DCRC (double crystal X-ray diffraction rocking curve). The optical energy gaps were found to be 2.61 eV for
single crystal thin films at room temperature. The temperature dependence of the photocurrent peak energy is well explained by the Varshni equation, then the constants in the Varshni equation are given by
. from the photocurrent spectra by illumination of polarized light of the
single crystal thin film, we have found that crystal field splitting
Cr was 0.28 eV at 20 K. From the PL spectra at 20 K, the peaks corresponding to free and bound excitons and a broad emission band due to D-A pairs are identified. The binding energy of the free excitons are determined to be 0.2676 eV and 0.2430 eV and the dissociation energy of the bound excitons to be 0.4695 eV.
The improvement in the properties of
films by the application of amorphous layer
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 221~226
Amorphous (Ba, Sr)
[BST] layer(30, 70 nm) was introduced between crystalline BST and
electrode to realize double-layered BST structure in order to improve the properties of BST film. The structure and surface morphology of double-layered BST film were modified by the application of amorphous BST layer; that is, surface became smoother and grain size increased abruptly. Amorphous layer thicker than 30 nm was effective to hinder the influence of
surface on the structure of as-grown BST films by in-situ process. Dielectric constant of double-layered BST film was improved dramatically from 152 to 340 and leakage current was lowered from
Synthesis of diamond thin films by hot-filament C.V.D
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 227~232
Diamond crystallization and discontinuous deposit phenomena depend on the process of hydrocarbon deposition, nucleation and growth. Then, it is investigated the concentration of methane, flow rate, structure and the growth process of
system in hot filament assisted C.V.D. There is a limited value of temperature, pressure, flow rate and the mole fraction of methane-hydrogen gas. Diamond nucleation occurs on substrate selectively and surface diffusion of species on the substrate plays an important role in the early stages of nucleation and growth.
A study on the SiC selective deposition
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 233~239
SiC thin films were deposited by chemical vapor deposition method using tetramethylsilane (TMS) and hexamethyldisilane (HMDS). The chamber pressure during the deposition was kept at about 1 torr. Precursor was transported to the reaction chamber by
gas and SiC deposition was carried out at the reaction temperature of
. Si-wafer masked with tantalum and MgO single crystal covered with platinum and molybdenum were used as substrates. The selectivity of SiC deposition was observed by comparing the microstructure between metal (Ta, Pt, and Mo) surfaces and substrate surfaces (Si and MgO). The deposited films were identified as the
phase by X-ray diffraction pattern. Also, the deposition -behavior of SiC on each surface was investigated by the scanning electron microscope analysis.
The use of spectroscopic Ellipsometey for the observation of diamond thin film growth by microwave plasma chemical vapor deposition
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 240~248
The plasma chemical vapor deposition is one of the most utilized techniques for the diamond growth. As the applications of diamond thin films prepared by plasma chemical vapor deposition(CVD) techniques become more demanding, improved fine-tuning and control of the process are required. The important parameters in diamond film deposition include the substrate temperature,
gas flow ratio, total, gas pressure, and gas excitation power. With the spectroscopic ellipsometry, the substrate temperature as well as the various parameters of the film can be determined without the physical contact and the destructiveness under the extreme environment associated with the diamond film deposition. It is introduced how the real-time spectroscopic ellipsometry is used and the data are analyzed with the view of getting the growth condition and the accompanied features for a good quality of diamond films. And it is determined the important parameters during the diamond film growth, which include the final sample will be measured with Raman spectroscopy to confirm the diamond component included in the film.
Wet chemical etching of GaN
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 249~254
The etching experiments for n-GaN were done using the wet chemical, photo-enhanced-chemical and electro-chemical etching methods. The experimental results show that n-GaN is etched is diluted NaOH solution at room temperature and the removed thickness of n-GaN is linearly increased with etching times. The etching rate of the photo-enhanced-chemical and electro-chemical etching methods are several times higher than that of the wet chemical method. The maximum etching rate of n-GaN with
/min under the experimental condition of the Photo-enhanced-chemical etching. The etching rates of n-GaN are very much dependant on the electron concentrations of the samples. The pattern is
rectangulars covered with
film. It is shown that the etched side-wall charactistics of the pattern is vertical without dependance of the n-GaN orientations, and the smoothness of etched n-GaN surface is fairly flat.
The crystal growth of amorphous materials in a 2.45 GHz microwave field
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 255~262
This study investigated the crystallization behaviour of sealing amorphous material heat-treated by conventional and microwave heating source. From X-ray diffraction and SEM analyses, it was shown that microwave heat-treated sample had well-grown
crystals and the high degree of crystallinity inspite of its heat-treated condition of shorten time and lower temperature as compared with a conventionally heat-treated sample. It was assumed that microwaves inhibit the nucleation of
crystal in nucleation stage, but promote the growth of
crystal above the critical size of crystal due to enhanced diffusion effect within the sample.
Dependence of defects on growth rate in (100) ZnSe cryseal
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 263~268
(100) ZnSe crystals with twin and grain free were grown by vapor transport method. The defect in (100) ZnSe crystals was investigated by FWHM of X-ray Rocking Curve. The growth rate and seed quality are the main parameters of the growth process to obtain the high quality ZnSe crystals. The geometric shape of the grown (100) ZnSe crystal is dependent on the shape of seed, isothermal line in furnace and the growth rate of each surface in crystal.
A study on crystallization of a-Si:H films
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 269~277
The crystallization method determines the material quality and consequent device performance. This paper investigates the crystallization of a-Si:H films on various substrate materials and analyzes the crystallization effect with and without using eutectic forming metals. From the examinations of the various substrate materials, a metal Mo was selected for the a-Si:H films growth and subsequent crystallization of it. For a sample without any eutectic metal layer, we observed grain size of
anneal treatment. To reduce crystallization temperature, we used some of the eutectic forming metals such as Au, Al and Ag. Poly-Si films with grain size over
and (111) preferential plains were achieved using a premetal layer of Au at an anneal temperature of
. The various crystallization effects of eutectic metal thickness and type were investigated for photovoltaic (PV) device applications.
A study of crystal growth and phase transition in
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 278~285
It was known that the C-IC transition in the mixed crystal
is smeared out with increasing x, which is attributed to the pinning effect of the doped A' ions. In this study, we introduce a new mixed crystal system
, where doped Co ions do not destroy the orientation of the polarization in C phase and preserve the long range ordering of IC phase. We grew a series of mixed crystals
for x=0, 0.001, 0.005, 0.01, 0.05, 0.1, 0.3, 0.5, 0.7, 1 by the Czochralski method and investigated the real composition of the mixed crystals, structure and the change of the C-IC phase transition with increasing x by the thermal analysis.
The effects of oxygen partial pressure on
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 286~291
[ST] thin films were fabricated on
bottom electrodes by RF magnetron sputtering with various
ratio in sputtering gas. As the content of oxygen increases, the leakage current of ST films measured at
V/cm decreases from
, and the dielectric constant of ST films increases from
. The improvement of electrical properties of ST films is mainly due to the structural modification of ST films such as better crystallinity, smooth surface morphology with the increase of oxygen content in the sputtering gas.
A study on the preparation of
films by dip-coating method
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 292~298
films were prepared by a dip-coating method using the mixed solution of ferric nitrate, ethylene glycol and acethyl acetone. The polymerization effect of the mixed solution was studied by FT-IR spectroscopic analysis, and the decomposition of organic parts and crystallization of the dip-coated film were investigated by FT-IR, XRD and DSC. In addition, AFM and SEM were employed to analyze the surface roughness and the thickness of
Effect of mechanical damage on the crystallization of amorphous silicon thin film
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 299~306
Crystallization of the amorphous silicon needs activation. Thermal energy through laser annealing, furnace annealing and rapid thermal process (RTP) has been convinced to crystallize the amorphous silicon thin film. It is expected that some other type of energy like mechanical energy can help to crystallize the amorphous silicon thin film. In this study, mechanical energy through wet blasting of silica slurry and silicon ion implantation has been applied to the amorphous silicon thin film deposited with LPCVD technique. RTP was employed for the annealing of this mechanically-damaged amorphous silicon thin film. For the characterization of the crystallized silicon thin film, XRD and Raman analysis were conducted. In this study, it is shown that the mechanical damage is effective to enhance the crystallization of amorphous silicon thin film.
Effect of buffer layers on preparation of Sol-Gel processed PZT thin films
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 307~314
PZT thin films were fabricated by the Sol-gel method. Starting materials used for the preparation of the stock solution were Pb-acetate trihydrate, Zr-normal propoxide and Ti-isopropoxide. 2-Methoxyethanol and iso-propanol were used for solution. For studying the diffusion of Pb ion into the substrates. We used bare Si substrate,
substrates which was produced by thermal oxidation and
which was mad by Sol-gel method. Densification and adhesion of thin films were observed by SEM. Phase formation of thin films and diffusion of Pb ion into the substrate were examined by XRD and ESCA, respectively. In the case of bare Si and
substrate, we obtained the perovskite phase at
and restricted a little the diffusion of Si ion into the film with
buffer layer. In the case of
, perovskite phase were obtained at
and the diffusion of Pb ion and Si ion were restriced.
Effects of additives on properties of Sol-Gel derived
coating films for nonlinear optics
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 315~323
films of rutile and anatase phase have been prepared on silica glass substrates by the sol-gel method using
. The effect of additives on the polymorph of
film has been examined in view of degree of crystallization. Third-order nonlinear optical properties of the both film have been investigated by the third harmonic generation method. The measured 3rd order nonlinear optical susceptibility of rutile and anatase thin films were about
Microstructural evolution in liquid-phase sintered
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 324~331
After the addition of yttrium aluminum garnet of 2, 5, 10 mol% as a sintering aid,
-silicon carbides were prepared by a liquid-phase sintering at
, and the microstructural evolution was investigated during sintering as functions of liquid-phase amount and sintering time. The highest apparent density in each compositions was obtained in specimens sintered for 2 h, and the percentage of weight loss increased with sintering time. By increasing the amount of sintering aid (yttrium aluminum garnet), the rate of grain growth during sintering decreased, but the apparent density of sintered body increased. The phase transformation from 6H-SiC to 4H-SiC was partially observed in specimens sintered for a long time, and so, a few rod-like grains were observed.
Solid-state reaction kinetics for the formation of mullite(
) from amorphous
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 332~341
Reaction kinetics for the solid - state reaction of
to produce mullite (
) was studied in the temperature range of 1450~
. Rate of kinetic reaction were determined by using
compact containing 28.16 wt.%
and heating the reactant mixtures in MgO at definite temperature for various times. Amount of products and unreacted reactants were determined by X-ray diffractometry. Data from the volume fraction and ratio of peak intensities of mullite indicated that the reaction of
start between 1450 and
. The activation energy for solid-state reaction was determined by using the Arrhenius equation; The activation energy was 31.9 kJ/mol.
The study on the formation of titanic acid by dehydration of TiCl₄
Kim, Heon ; Kim, Dae Ung ; Lee, Gyeong Hui ; Baek, Un Pil ;
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 342~342
The effect of pH on the dehydration reaction of TiCl₄solution. KOH and HCl were used as a accelerater and retarder in dehydration. Results are follow. Neutralization point is pH 7.4 in the system of
and the production which is produced at acidic side is Ti-gel of poly metatitanic acid. The production which is produced at alkalic side is aligomer and crystalline potasium titanate is not detected.
The study on the formation of titanic acid by dehydration of TiCl4
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 343~349
The effect of pH on the dehydration reaction of
solution. KOH and HC1 were used as a accelerater and retarder in dehydration. Results are follow. Neutralization point is pH 7.4 in the system of
- KOH and the production which is produced at acidic side is Ti -gel of poly metatitanic acid. The production which is produced at alkalic side is aligomer and crystalline potasium titanate is not detected.
A preparation of dysprosium monotitanate powder by mixed-oxide ceramics processing employing polymer carrier
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 350~355
powder was synthesized by a simple mixed-oxide ceramics process using ethylene glycol (EG). Ethylene glycol, as the organic carrier for the metal cations, was used for polymerization mechanism. The successful used of a non-chelating polymer for the mixed-oxide ceramic process indicated that cation chelation is not the only route for creating stable ceramic precursors. Characterization of the powders by various thermal analysis, microscopy, and diffraction methods has been carried out.
Optimization of powder compaction parameters for the pressureless sintered ZTA
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 356~364
The dependence of green and sintered densities of Zirconia-Toughened Alumina (
) on the properties of spray-dried granules was studied thoroughly to establish the optimum compaction condition leading to high reproducibility in the light of sintered density. The sphericity, mean size, degree of hollow occurrence and moisture content of spray-dried granules were largely different in between the granule containing binder and the ones with no binder. The effect of these differences in the characteristic of granules on the compaction behavior was examined in terms of the compaction pressure from 80 MPa to 120 MPa 10 MPa increment and the compaction method, i.e., uniaxial and cold isostatic pressing. This work confirmed that the reproducibility of sintered density caused by the variation of granule property could be improved by the optimization of compaction process. The variation of sintered density was controlled within 1 % deviation by compacting the granules under a relatively low pressure of 80 MPa in an uniaxial forming and subsequent cold isostatic pressing at high pressure of 500 MPa.
On the unsaturation adsorption phenomena : consideration through the adsorption isotherm
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 365~369
Theory of the adsorption by a monolayer is extended to the multiple adsorption layers. Though the model used is extremely simple, the adsorption isotherm thus obtained describes well qualitatively the nature of unsaturation adsorptions such as
adsorption by the silica gel.
The preparation of Zinc-Silicate phosphors by noble technique
Journal of the Korean Crystal Growth and Crystal Technology, volume 8, issue 2, 1998, Pages 370~376
The powder preparation of Zinc-Silicate phosphors compound was studied by hydrothermal reaction starting from the precursor which prepared by spray pyrolysis method. This process protect including of impuritied from crushing process and Mineralizing in hydrothermal reactions. Using spray pyrolysis precursor,
powder was prepared by the hydrothermal reaction under