• Korean Journal of Materials Research
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• v.4 no.6
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• pp.644-650
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• 1994

The submicron powders of high-purity silicon have been produced by Electrohydrodynamic Atomization. Field-emission scanning transmission electron microscopy(STEM) is used to determine the microstructure and solidification phase. .Then it is found that the droplets less than 60nm diameter are solidified as the amorphous phase. A useful and accessible characterization of atomic arrangements in amorphous solids can be given in terms of a radial distribution function. According to experimental determinations of the radial distribution function for amorphous silicon, its similarity to the crystalline structure at small radial distances indicates that the basic tetrahedral arrangement found in the diamond cubic structure of silicon must be maintained in the amorphous structure.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.4
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• pp.664-669
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• 2018

To observe the relationship between the oxygen vacancy and electrical characteristics of $TiO_2$ due to the $CO_2$ gases, the $TiO_2$ were deposited by the mixing gases of $Ar:O_2=20$ sccm:20 sccm and annealed with various temperatures. The bonding structure was changed with the annealing temperature from amorphous to crystal structure, and the oxygen vacancy was also changed with these bonding structures. The $CO_2$ gas reaction of $TiO_2$ films showed the variation in accordance with the bonding structure. The capacitance increased at the amorphous structure $TiO_2$, and the current also increased. However the oxygen vacancy decreased at this amorphous structure $TiO_2$. Because of the formation of oxygen vacancies is in inverse proportion to the amorphous structure. Moreover, the diffusion current in the depletion layer such as the amorphous structure showed the difference in accordance with the $CO_2$ gas flow rates.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.767-771
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• 1995

The atomic structure and magnetic properties of $LaCo_{13}$ amorphous alloy have been investigated and compared with those of its crystalline counterpart. It has been confirmed that the amorphous alloy is composed of the icosahedral clusters with a $NaZn_{13}$-type structure. The magnetic moment and the spin- wave stiffness constant obtained from the magnetic measurements in the amorphous state are larger than those in the crystalline state. The Curie temperature estimated from the reduced magnetization curve for the former is much higher than the value for the latter. The localized magnetic moment character in the amorphous state is stronger than that in the crystalline state.

• Journal of the Korean Society for Heat Treatment
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• v.12 no.4
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• pp.320-326
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• 1999

In rapidly solidified $Al_{92-x}Nd_8$(Cu,Ag)x ($0{\leq}X{\leq}10at%$) alloys, amorphous single phases were obtained in the ranges of $Oat%{\leq}X{\leq}4at%$ for Al-Nd-Cu system and $Oat%{\leq}X{\leq}6at%$ for Al-Nd-Ag system, respectively. Mesoscopic structures consisted of amorphous and crystalline phases were formed above solute ranges. It was founded that the mesoscopic structures were also formed near 1st exothermic peak on DSC curve by aging in amorphous single phase alloys. For example, amorphous $Al_{92-x}Nd_8$(Cu,Ag)x (X=2.4at%) alloys containing nanoscale Al particles and compounds, i.e., mesoscopic structure, exhibited higher tensile fracture strength(${\sigma}_f$) than those of amorphous single phase alloys with the same composition. The ${\sigma}_f$ showed a maximum value in the $V_f$ ranges of 10~15%. The reason is presumed that the nanoscale precipitates which have higher mechanical strength compared with the amorphous phase with the same composition act as an effective resistance to shear deformation of the amorphous matrix.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.889-892
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• 2000

We have investigated the Pt doping effect on structural and electrochemical properties of amorphous vanadium oxide film, grown by radio frequency magnetron sputtering. Room temperature charge-discharge measurements based on a half-cell with a constant current clearly indicated that the Pt doping could improve the cyclibility of V$_2$O$_{5}$ cathode film. Using glancing angle x-ray diffraction (GXRD) and high resolution transmission electron microscopy (HRTEM) analysis, we found that the Pt doping with l0W r.f. power induce more random amorphous structure than undoped V$_2$O$_{5}$ film. As the r.f. power of Pt increases, large amount of Pt incorporates into amorphous V$_2$O$_{5}$ and makes PtOx microcrystalline phase in amorphous matrix. This result suggests that the semicondcuting PtOx microcrystalline phase in amorphous matrix lead to a drastically faded cyclibility of 50W Pt doped V$_2$O$_{5}$ cathode film. Possible explanations are given to describe the Pt doping effect on cyclibility of vanadium oxide cathode film.de film.

• Journal of the Korean institute of surface engineering
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• v.20 no.4
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• pp.154-162
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• 1987

The recent literatures on the amorphous plating are reviewed. The methods of the amorphous plating are classified into the electrodeposition and electroless deposition. The structure and properties of the amorphous deposits, and the prospect in the future on the amorphous plating are discussed.

• Journal of Welding and Joining
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• v.17 no.4
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• pp.53-59
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• 1999

Amorphous alloys have also been called glassy alloys or non-crystalline alloys. They are made by the rapid solidification. The solidification occurs so rapid that the atoms are frozen in their liquid configuration. There are unique magnetic, mechanical, electrical and corrosive behaviors which result form their amorphous structure. In the study. amorphous coatings were manufactured with Ni-Cr-B-Si powders by flame spray. Measurement of hardness, were resistance, corrosion resistance and observation of microstructures and XRD, DSC were performed to investigate characteristics of amorphous coatings. The experimental results obtained as follow: 1) Amorphous powders could not be manufactured with the spraying in the spraying in the liquid nitrogen. But, amorphous coatings could be manufactured with the rotation cooling method by liquid nitrogen. In the fabrication of amorphous coatings, major factor was the rapid cooling by rotation of the substrate. 2) Hardness of coatings was obtained Hv 960 by formation of amorphous phase. But, wear resistance decreased. That was due to porosity in the coatings by the rapid cooling. 3) In the case of corrosion resistance, amorphous coatings were superior to air-cooled coatings. That was due to formation of amorphous phase. 4) After amorphous coatings were heat-treated at 520℃ for 1hr. hardness increased 80% and wear resistance increased 30% comparing with air cooled coatings. These were due to crystallization of amorphous phase and decrease of porosity by heat-treatment.

• Journal of Powder Materials
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• v.10 no.4
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• pp.288-293
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• 2003

Mechanical alloying (MA) by high energy ball mill of Pure chromium Powders was carried out under the nitrogen gas atmosphere. Cr-N amorphous alloy powders have been produced through the solid-gas reaction subjected to MA. The atomic structure during amorphization process was observed by X-ray and neutron diffractions. An advantage of the neutron diffraction technique allows us to observe the local atomic structure surrounding a nitrogen atom. The coordination number of metal atoms around a N atom turns out to be 5.5 atoms. This implies that a nitrogen atom is located at both of centers of the tetrahedron and octahedron formed by metal atoms to stabilize an amorphous Cr-N structure. Also, we have revealed that a Cr-N amorphous alloy may produced from a mixture of pure Cr and Cr nitrides powders by solid-solid reaction during mechanical alloying.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.164-164
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• 2010

The impurity doped ZnO has been extensively studied because of its optoelectric properties. GIZO (Ga-In-Zn-O) amorphous oxide semiconductors has been widely used as transparent flexible semiconductor material. Recently, various amorphous transparent semiconductors such as IZO (In-Zn-O), GIZO, and HIZO (Hf-In-Zn-O) were developed. In this work, we examined the local structures of IZO, GIZO, and HIZO. The local coordination structure was investigated by the extended X-ray absorption fine structure. The IZO, GIZO and HIZO thin films ware deposited on the glass substrate with thickness of 400nm by the radio frequency sputtering method. The targets were prepared by the mixture of $In_2O_3$, ZnO and $HfO_2$ powders. The percent ratio of In:Zn in IZO, Ga:In:Zn in GIZO and Hf:In:Zn in HIZO was 45:55, 33:33:33 and 10:35:55, respectively. In this work, we found that IZO, GIZO and HIZO are all amorphous and have a similar local structure. Also, we obtained the bond distances of $d_{Ga-O}=1.85\;{\AA}$, $d_{Zn-O}=1.98\;{\AA}$, $d_{Hf-O}=2.08\;{\AA}$, $d_{In-O}=2.13\;{\AA}$.

• Journal of the Semiconductor & Display Technology
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• v.14 no.4
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• pp.20-24
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• 2015

This study was explained the correlation between the O 1s spectra and the crystallization of ITO thin films. The crystal structure of ITO thin films changed with various annealing temperatures and annealing methods such as atmosphere or vaccum conditions. The amorphous structure observed from XRD pattern showed the O 1s spectra with 531.2 eV, and the crystal structure of annealed ITO films analyzed by XRD pattern had the O 1s spectra of 529.8 eV as lower binding energy then the 531.2 eV. Oxygen in view of ITO films was related to the crystallization, and the ITO films annealed in an atmosphere pressure showed higher crystal structure than the ITO annealed in a vaccum. It was indicated that the amorphous structure had higher binding energy than the crystal structure analyzed by O 1s spectra of ITO films.