• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.487-490
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• 1995

With the object of developing a new magnetic core materials for high frequency use, the crystallization behaviors and the soft magnetic properties of amorphous $F_{86-x}Al_{4}B_{10}Zr_{x}\;(5{\leq}x{\leq}10\;at%)$ alloys subjected to annealing treatment at wide temperature range were investigated. For optimally annealed $Fe_{86-x}Al_{4}B_{10}Zr_{x}$ alloys in amorphous state, rather good soft magnetic properties of ${\mu}_{e}=17000~25000,\;H_{c}=20~30$ mOe and $B_{10}{\geq}0.6$ T are obtained. However, as the alloys crystallize, the soft magnetic properties are largely dergely deteriorated, which is attributed principally to the narrow temperature gap between $T_{x1}$ and $T_{x2}$, which allows the nearly co-precipitation of bcc phase and Fe-B compounds in incipient crystallization stage.

• Journal of the Korean Society for Heat Treatment
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• v.17 no.5
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• pp.271-277
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• 2004

Zr-xNb alloys (x = 0.2, 0.8, 1.5 wt.%) were prepared to study the characteristics of the phase transformation in Zr-Nb system. The samples were heat treated at ${\beta}$-temperature ($1020^{\circ}C$) for 20 min and then cooled with different cooling rate. The microstructures of the specimens having the same compositions were changed with cooling rate and Nb content. The Widmanst$\ddot{a}$tten structure was observed on the furnace-cooled sample. The relationship between ${\alpha}$-Widmanst$\ddot{a}$tten and ${\beta}$-phase was the {0001}${\alpha}$//{110}${\beta}$, <11$\bar{2}$0>//<111>. The ${\beta}$-phase in Widmanst$\ddot{a}$tten structure of Zr-Nb alloys containing Nb more than solubility limit was identified as ${\beta}_{Zr}$ phase which was a stable phase at high temperature. In the water quenched samples, two kinds of martensite structures were observed depending on the Nb-concentration. The lath martensite was formed in Zr-0.2, 0.8 wt.% Nb alloys and the plate martensite having twins was formed in Zr-1.5 wt.% Nb alloy.

• Journal of the Korean Magnetics Society
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• v.2 no.1
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• pp.1-7
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• 1992

Deuterium was injected into melt-spun ribbons of ${\alpha}-Fe_{90}Zr_{10}$ using the electrolytic hydrogenation method, and the magnetic properties of these ${\alpha}-D_{x}Fe_{90}Zr_{10}$ ribbons were studied. By comparing these results with those of ${\alpha}-H_{x}Fe_{91}Zr_{9}$, the effects of phonons to magnetic properties were investigated. The Curie temperature $T_{c}$, and the spontaneous magnetizations of the $D_{47}Fe_{90}Zr_{10}$ and the $Fe_{90}Zr_{10}$ were studied using the Mbssbauer spectroscopy. From these investigations, it was found that the Curie temperature of $D_{x}Fe_{90}Zr_{10}$ was 75K higher than that of $Fe_{90}Zr_{10}$. It was believed that this indicated the importance of local deformation to the amorphous magnetism. Also by comparing the spontaneous magnetizations of $D_{47}Fe_{90}Zr_{10}$ with those of $Fe_{90}Zr_{10}$ as a function of temperature, it was found that the deuterium injection reduced the fluctuation of exchange integral.

• Journal of the Korean Society for Heat Treatment
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• v.20 no.6
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• pp.299-305
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• 2007

The effect of spray deposition of oxide particles on oxidation behaviors of as-cast Mo-14.2Si-9.6B (at%) alloys at $1200^{\circ}C$ up to for 100 hrs has been investigated. Various oxide powders are utilized to make coatings by spray deposition, including $SiO_2,\;TiO_2,\;ZrO_2,\;HfO_2$ and $La_2O_3$. It is demonstrated that the oxidation resistance of the cast Mo-Si-B alloy can be significantly improved by coating with those oxide particles. The growth of the oxide layer is reduced for the oxide particle coated Mo-Si-B alloy. Especially, for the alloy with $ZrO_2$ coating, the thickness of oxide layer becomes only one fifth of that of uncoated alloys when exposed to in air for 100 hrs. The reduction of oxide scale growth of the cast Mo-Si-B alloy due to oxide particle coatings are discussed in terms of the change of viscosity of glassy oxide phases that form during oxidation at high temperature.

• Journal of the Korean Vacuum Society
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• v.17 no.4
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• pp.317-321
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• 2008

The $0.65Pb(Mg_{1/3}Ta_{2/3})O_3-0.35PbTiO_3$ (PMT-PT)ceramics were near morphotropic phase boundary. The dielectric constant, the loss, and pyroelectric coefficient of the ceramics were measured as a function of temperature ($25^{\circ}C\;{\sim}\;250^{\circ}C$). The dielectric constant, the loss, and the pyroelectric coefficient could be improved with the addition of small amounts of $ZrO_2$ up to 0.2 mol%. The dielectric and pyroelectric peak temperature are slightly shifted to lower temperatrues with the addition of amount of $ZrO_2$.

• Journal of the Microelectronics and Packaging Society
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• v.6 no.1
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• pp.51-58
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• 1999

The effects of glass composition on the wettability and reactivity with $ZrO_2$substrate was evaluated and fabrication variables and glass compositions was investigated. Various glass compositions was investigated. Alkaline earth silicate glass show good wettability and lower viscosity and crystallization of glass could be prevented by $B_2O_3$.The sealant glass begin to wet on $ZrO_2$substrate below $900^{\circ}C$ and porosity occurred in various glass compositions, the crystallization and porosity in the glass could be prevented by the addition of flux into glass composition. But flowability and reactivity of glass with $ZrO_2$substrate was enhanced. Processing variables should be optimized to reduce the porosity by enhancing the sintering of glass powder. Many silicate glasses were investigated for the applications of high temperature sealants. Wetting and bonding of glass was good enough to seal together between $ZrO_2$and other ceramic components of SOFC. But porosity and reaction layer were occurred in the sealant glass. It will be possible to produce glass sealant without porosity and reaction layer at the interface by optimization of processing variable and modify the glass compositions. In present study, wettability of glass-filler composite was investigated. The porosity, shape of filler and interfacial reactions of sealant glass with fillers were examined.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.13-16
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• 2000

In this study, we have fabricated nonequilibrium $Fe_{85.6}Zr_{3.3}B_{5.7}Ag_{5.4}$ thin film, which contains an additional insoluble element Ag, by using DC magnetron sputtering method. We have investigated the magnetic properties of amorphous $Fe_{85.6}Zr_{3.3}B_{5.7}Ag_{5.4}$ thin film as a function of rotational field annealing(RFA). After deposition, the amorphous $Fe_{85.6}Zr_{3.3}B_{5.7}Ag_{5.4}$ thin film annealed by rotational field annealing method at $350^{\circ}C$ for an hour was founded to have high permeability of 8680 of 100 MHz, 0.2 mOe, low coercivity of 0.86 De and very low core loss of 1.3 W/cc at 1 MHz, 0.1T.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.4
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• pp.153-159
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• 2015

Inorganic pigments have been received a great attention for various applications including paint, glazed ceramic ink, art tile, and building exterior due to their excellent thermal and chemical stability. Traditionally, the compositions of $PbCrO_4$, CdS and CdSe have been widely used as a yellow inorganic pigment. However, the use of these compositions has been restricted in recent years, because they contain harmful elements such as Cd, Cr, Pb and Se. In this study, new environment-friendly ceria-based pigment was synthesized using solid state reaction. Crystal structure and morphology of the obtained $Ce_{1-x}Zr_xBi_yO_{2-y/2}$ yellow pigment were analyzed using XRD and SEM, respectively. Substitutional effect of Zr and Bi on the pigment color was analyzed using UV-vis. spectrophotometer and CIE $L^*a^*b^*$ analysis. The crystal structure of the obtained pigments was dependent on the calcination temperature. The color characteristics and absorption band of the pigments were dependent on the calcination temperature and Zr, Bi contents. As a result, all the obtained yellow pigments showed the effective absorption ranged from ultraviolet to visible light, and $Ce_{0.44}Zr_{0.36}Bi_{0.20}O_{0.19}$ (x = 0.36, y = 0.20) pigment showed the most brilliant yellow color.

• Korean Journal of Materials Research
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• v.14 no.10
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• pp.713-718
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• 2004

To study the dynamic strain aging behavior of Zr-0.4Sn-1.5Nb-0.2Fe sample tube for nuclear fuel cladding in the range of pressurized water reactor (PWR) operation temperature, the tensile tests of the tube specimens, which had been finally heat-treated at $470^{\circ}C\;and\;510^{\circ}C$, had been carried out with the strain rate $1.67{\times}10^{-2}/s\;and\;8.33{\times}10^{-5}/s$ at the various temperatures from room temperature to $500^{\circ}C$. It was observed that the elongation of the specimens got shortened as the temperature increased from $200^{\circ}C\;to\;340^{\circ}C$. The specimens that were finally heat-treated at $470^{\circ}C$ showed a plateau more remarkably on the plot of yield strength-temperature than those heat-treated at $510^{\circ}C$. In the range of $310\sim400^{\circ}C$, the strain rate sensitivity of the specimens finally heat-treated at $510^{\circ}C$ was $30.4\%\sim33.7\%$ lower but the work hardening exponent index of the specimens was a little higher than that without dynamic strain aging effect.

• Transactions of the Korean hydrogen and new energy society
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• v.17 no.1
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• pp.55-61
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• 2006

신규 $Nb_2Zr_6O_{17-x}N_x$ 광촉매를 고상합성법처리(solid state synthesis) 후 암모니아가스($NH_3$)에 의한 기상처리법(ammonolysis)으로 합성하였다. 합성된 신규 광촉매 및 이를 다시 Pt 및 $RuO_2$를 도핑 하여 $H_2S$를 광분해하여 수소를 발생 실험을 수행하였다. 이 신규 oxynitrid계 광촉매는 가시광하에서 $H_2S$를 광분해하여 수소를 발생하는(Quantum yield = 13.5 %) 우수한 광촉매 활성을 보여주었다.