• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.370-370
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• 2010

The effects of adding higher-valence impurities on the bipolar resistive switching characteristics of Pt/$NiO_{1+x}$/TiN MIM stacks and physical properties were investigated. $NiO_{1+x}$ films with 14% W deposited at 20% oxygen partial pressure exhibited the bipolar resistance switching characteristics in Pt/$NiO_{1+x}$/TiN MIM stacks, while $NiO_{1+x}$ films with 8.2% W show unipolar resistance switching behavior. The relationship of W-doping and the crystallinity was studied by X-ray diffraction. The metallic Ni contents and $WO_x$ binding states with W amount was investigated by XPS. Our result showed that the metallic Ni, $WO_x$ binding states, and crystallinity in $NiO_{1+x}$ played an important role on the bipolar resistive switching.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.8
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• pp.671-676
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• 2009

The $Sr_{0.7}Bi_{2.3}Nb_2O_9$(SBN) thin films are deposited on Pt-coated electrode(Pt/Ti/$SiO_2$/Si) using RF sputtering method at various deposition conditions. We investigated the effect of deposition condition on the surface morphology and dielectric properties of SBN thin films. The optimum of the rougness showed about 4.33 nm in 70/30 of Ar/$O_2$ ratio. The crystallinity and rougness of SBN thin films were increased with the increase of rf power. Also, Deposition rate of SBN thin films was about 4.17 nm/min in 70 W of rf power. The capacitance of SBN thin films were increased with the increase of Ar/$O_2$ ratio, rf power and deposition temperature respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.213-214
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• 2008

The $Sr_{0.7}Bi_{2.3}Nb_2O_9$(SBN) thin films are deposited on Pt-coated electrode(Pt/Ti/SiO2/Si) using RF sputtering method at various substrate temperature. The optimum conditions of RF power and Ar/O2 ratio were 60[W] and 70/30, respectively. The crystallinity of SBN thin films were increased with increase of substrate temperature in the temperature range of 100~400[$^{\circ}C$]. The capacitance of SBN thin films were increased with the increase of substrate temperature.

• Textile Coloration and Finishing
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• v.15 no.2
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• pp.102-108
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• 2003

Before studying graft polymerization of PP(polypropylene) nonwoven fabrics by electron beam preirradiation method, mechanical properties, thermal properties and degree of crystallinity of original and electron beam irradiated PP nonwoven fabrics were investigated. Morphological surface changes of electron beam irradiated PP nonwoven fabrics were not observed. And the melting temperature and crystallinity of electron beam irradiated PP nonwoven fabrics also did not change as compared with untreated PP nonwoven fabrics. But the breaking strength of electron beam irradiated PP nonwoven fabrics decreased with increasing electron beam absorbed dose due to breakdown of some parts of polymer main chain.

• Journal of the Korean Ceramic Society
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• v.27 no.4
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• pp.521-528
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• 1990

Li2O.2SiO2 glass-ceramics were made from the melt by the nucleation and growth treatment. The optimum nucleation temperature and time were determined from DTA curves of as-quenched and thermally treated glasses, and found to be 44$0^{\circ}C$ and 3hrs. The optical microscopic technique was also used to support this result. The volume fractions of crystals present in the partially crystallized specimens were measured using the optical microscopy and the amorphous X-ray scattering methods. The degree of crystallization increased with increasing the crystallization temperature and time. The crystalline phase identified by X-ray diffraction was lithium disilicate. As the crystallinity increased up to 95%, the transmittance of glass-ceramics was decreased linearly. It was also found that for the same heat treatment condition (575$^{\circ}C$, 30min), a thicker specimen showed higher transmittance, presumably due to less crystallinity.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.302.1-302.1
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• 2014

We report the growth of high quality zinc oxide (ZnO) thin films on amorphous glass substrates and their structural and optical characteristics. For the growth of ZnO films, mechanically exfoliated ultrathin graphite or graphene layers were used as an intermediate layer because ZnO does not have any heteroepitaxial relationship with the amorphous substrates, which significantly improved the crystallinity of the ZnO films. Structural and optical characteristics of the films were investigated using scanning and transmission electron microscopy, x-ray diffraction, and variable temperature photoluminescence spectroscopy. High crystallinity and excellent optical characteristics such as stimulated emission were exhibited from the high quality ZnO films grown on glass substrates.

• Applied Science and Convergence Technology
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• v.24 no.6
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• pp.268-272
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• 2015

We report the systematic study to reduce extrinsic doping in graphene grown by chemical vapor deposition (CVD). To investigate the effect of crystallinity of graphene on the extent of the extrinsic doping, graphene samples with different levels of crystal quality: poly-crystalline and single-crystalline graphene (PCG and SCG), are employed. The graphene suspended in air is almost undoped regardless of its crystallinity, whereas graphene placed on an $SiO_2/Si$ substrate is spontaneously p-doped. The extent of p-doping from the $SiO_2$ substrate in SCG is slightly lower than that in PCG, implying that the defects in graphene play roles in charge transfer. However, after annealing treatment, both PCG and SCG are heavily p-doped due to increased interaction with the underlying substrate. Extrinsic doping dramatically decreases after annealing treatment when PCG and SCG are placed on the top of hexagonal boron nitride (h-BN) substrate, confirming that h-BN is the ideal substrate for reducing extrinsic doping in CVD graphene.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.3
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• pp.108-114
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• 2008

Uniaxial tension and compression test were conducted on conventional and crosslinked ultra-high molecular polyethylene (UHMWPE) all prepared from the same lot of medical grade GUR 1050. The conventional materials were unirradiated and gamma irradiated with $25kGy{\sim}200kGy$. Gamma irradiated processing was found to significantly impact the crystallinity, and hence the mechanical behavior, of the highly crosslinked UHMWPE. The crystallinity and radiation dose were key predictors of the uniaxial yielding, hardness, plastic flow, and failure properties of conventional and highly crosslinked UHMWPE. The correlation model from experiments would be the basic information to design the liner of artificial joint.

• International Journal of Industrial Entomology and Biomaterials
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• v.28 no.1
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• pp.19-24
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• 2014

Silk has always been one of the most favored textile materials. Fully degummed silk fiber (i.e., silk fibers without sericin) shows better luster than raw silk fiber (with sericin); it is also softer. On the other hand, raw silk fiber feels cooler because of the presence of sericin, making it useful as a textile for the summer season. Recently, partially degummed silk has attracted researchers' attention because it provides better luster, feel, and dyeing properties. However, the partial degumming of silk is very difficult because it results in inhomogeneously degummed fiber. In the present study, silk yarns were degummed with surfactant aqueous solutions and the effects of each surfactant on the degumming ratio, crystallinity, and homogeneity of the degummed silk yarn were examined. The degumming ratio and crystallinity index of silk yarn varied depending on the type of surfactant. On the whole, anionic surfactants resulted in higher degumming ratios and better homogeneity than nonionic surfactants.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.11b
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• pp.149-152
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• 1999

A new process for deinking of colored offset newsprint, i.e. enzyme treatment in cooperation with ultrasonic wave was developed in the present study. The physical characteristics such as fiber length, coarseness, crystallinity index of the deinked pulps were investigated and the sugar residues released from the treatment were analyzed. It was found that colored offset newsprint could be deinked effectively by cellulase treatment when ultrasonic wave was applied. The brightness increased by 5% ISO over that of control experiment and the pigment content was reduced markedly. Though the ultrasonic wave had little effect on the strength and crystallinity of the pulp, the treatment of enzyme combined with ultrasonic wave reduced the coarseness and fiber length to some extent. It was also found that ultrasonic wave could accelerate the hydrolysis of cellulose and hemicellulose during the cellulase treatment.