• Korean Journal of Materials Research
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• v.10 no.11
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• pp.755-759
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• 2000

The influence of $O_2$partial presure on saturation magnetization, coercivity and effective permeability(0.5~100MHz) of as-deposited Fe-Sm-O thin films, which were fabricated by RF magnetron reactive sputtering method, were investigated. The nanocrystalline Fe(sub)83.4Sm(sub)3.4O(sub)13.2 thin film fabricated at $O_2$partial pressure of 5% exhibits the best magnetic softness with saturation magnetization of 18kG, coercivity of 0.82 Oe and effective permeability about 2,600 at 0.5~100MHz. $\alpha$-Fe grain size is decreased with increasing $O_2$partial pressure. In case of $O_2$partial pressure of 10%, it is observed that FeO compound is formed and soft magnetic properties are decreased. The electrical resistivity of Fe-Sm-O thin films were increased with increasing $O_2$partial pressure, the electrical resistivity of Fe(sub)83.4Sm(sub)3.4O(sub)13.2 thin film with the best soft magnetic properties was 130 $\mu$$\Omega$cm. Therefore, It is assumed that the good soft magnetic properties of Fe(sub)83.4Sm(sub)3.4O(sub)13.2 thin film results from high electrical resistivity and decreasing $\alpha$-Fe grain size due to precipitation of Sm-Oxide phase.

• Proceedings of the Korean Magnestics Society Conference
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• 1991.11a
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• pp.100-101
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• 1991

• Applied Microscopy
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• v.27 no.3
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• pp.235-241
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• 1997

The microstructure of intermixed $Zn_{1-x}Fe_xSe$ layers in the (ZnSe/FeSe) superstrates grown on (00l) GaAs substrates has been investigated by high -resolution transmission electron microscopy and computer simulations of lattice images. Computer image simulations have been performed by the multislice method under various sample thicknesses and defocusing conditions. The simulated lattice images were compared with the experimental lattice images. Also, CuAu-I type ordering was often observed in the intermixed $Zn_{1-x}Fe_xSe$ alloys. This CuAu-I type ordered structure consists of alternating ZnSe and FeSe monolayers along the <100> and <110> directions.

• Journal of the Korean Magnetics Society
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• v.9 no.6
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• pp.291-295
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• 1999

$NiFe/Co/Al_2O_3/Co/IrMn$ tunneling junctions were grown on (100)Si wafer and their spin-valve tunneling magnetoresistance (TMR) was studied. The tunneling junctions were grown by using a 5-gun RF/DC magnetron sputter. $Al_2O_3$ barrier layer was formed by exposing Al layer to oxygen atmosphere at 6$0^{\circ}C$ for 72 hours. Strong exchange coupling interaction is observed between the ferromagnetic Co and the antiferromagnetic IrMn of Co/IrMn bilayer when IrMn is 100$\AA$ thick. $NiFe(183\;{\AA})/Co(17\;{\AA})/Al_2O_3(16\;{\AA})/Co(100\;{\AA})/IrMn(100\;{\AA})$ tunneling junction shows best TMR ratio of about 10% in the applied magnetic field range of $\pm$20 Oe. The TMR ratio is improved about 23% and electrical resistance is decreased about 34% when annealed at 200 $^{\circ}C$ for 1 hour in magnetic field of 330 Oe, parallel to the bottom electrode. With increasing the active area of junction the TMR ratio increases while electrical resistance decreases.

• Journal of the Korean Magnetics Society
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• v.10 no.2
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• pp.67-73
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• 2000

Top spin valve samples with a structure Ta/NiFe/CoFe/Cu/CoFe/FeMn/Ta were deposited on a Si(100) substrate by changing d.c. magnetron sputtering conditions and the exchange-bias and magnetic properties of samples were investigated. The Exchange field, H$\_$ex/ increased with increase of sputtering power of FeMn from 30 to 150 W and CoFe from 30 to 100 W deposited on the Cu, the increase of H$\_$ex/ was found due to the improvement of preferred orientation of (111) FeMn phase from XRD results. In the case of Cu, H$\_$ex/ decreased with the increase of sputtering pressure ranging from 1 to 5 mTorr. The relationship between exchange field and resistance was investigated, spin valve samples with a large exchange field showed the lower resistance, which was strongly dependent on the good crystallinity and grain size increase as well as lower scattering effects. The Cu thickness was changed from 22 to 38 $\AA$ for Si/Ta/NiFe/CoFe/Cu(t), 30 W/CoFe, 100 W/FeMn, 100 W/Ta spin valve structures, MR ratio of 6.5 % and exchange field of about 190 Oe were obtained for the sample with Cu of 22 $\AA$ thickness. The increase of exchange field with decrease of Cu thickness was explained by FM/AFM spin-spin interaction.

• Journal of Animal Science and Technology
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• v.52 no.3
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• pp.221-228
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• 2010

The objective of the present study was to investigate the effects of Fe-soy proteinate chelate (Fe-SP) on sows milk, piglet blood parameters and performance. A total of 15 sows of 3 wk before parturition and pigs after births to 3 wk were assigned to three dietary treatments: control (sow-basal diet, piglets with Fe injection); Fe-SP 100 (Fe 100 ppm as Fe-SP in sow and piglet diet); Fe-SP 200 (Fe 200 ppm as Fe-SP in sow and piglet diet). Each treatment had 5 replicates (sows) of six piglets per sow randomly selected from the same offspring. For this experiment, Fe-SP was manufactured. There were no significant differences among treatments in number of pigs born in total or alive per litter, birth weight, number of pigs weaned per litter and weaning weight. However, weight gain, feed intake and feed conversion ratio significantly (p<0.05) decreased as the supplementation level of Fe-SP increased. There were no significant differences among treatments in Fe content at 3 wk before parturition in sow blood. However, Fe content at 2 wk before parturition in sow blood significantly (p<0.05) increased as the supplementation of Fe-SP. While there were no significant differences among treatments in Fe content at 1 wk before parturition in sow blood, it tended to increase as the supplementation level of Fe-SP increased. There were no significant differences among treatments in Fe content of sow milk. However, it tended to increase as the supplementation level of Fe-SP increased. Iron content in the blood of piglets was significantly (p<0.05) higher in control (Fe injected) than Fe-SP 100 and Fe-SP 200 treatments at $1^{st}$ and $2^{nd}$ wk but it was significantly higher in Fe-SP 200 than others in $3^{rd}$ wk. Zinc content in the blood also significantly (p<0.05) increased as the Fe-SP supplementation level increased in $3^{rd}$ wk. In conclusion, Fe-SP supplementation significantly affected Fe content in the blood of piglets. Iron injection was more effective at $1^{st}$ and $2^{nd}$ wk, while Fe-SP 200 supplementation was effective at $3^{rd}$ wk in improving blood Fe level in piglets.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.2
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• pp.69-73
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• 2018

Crystal growth of ${\alpha}-Fe_2O_3$ nanosized particles of 80~90 nm in size, which were hydrothermally prepared from 0.03 M $FeCl_3$ solution at $100^{\circ}C$, was investigated in Pb-containing and Pb-free frit. By heating ${\alpha}-Fe_2O_3$ nanosized particles in two frits at $800^{\circ}C$, the average diameter of particles in frits was increased to 200~210 nm and 150~160 nm, respectively, and the crystal growth due to the aggregation and sintering of several ${\alpha}-Fe_2O_3$ particles was observed. Formation ratios of larger particles over 100 nm in diameter were 54 % in Pb-free frit and 85 % in Pb-containing frit. After heating ${\alpha}-Fe_2O_3$ particles in frits at $800^{\circ}C$, 7~9 nm in average diameter of pores were formed in particles. Theses pores were derived from the porous structure of original ${\alpha}-Fe_2O_3$ particles and confined in particles during sintering.

• Resources Recycling
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• v.23 no.6
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• pp.22-29
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• 2014

Recycling process of iron should be developed for efficient recovery of neodymium (Nd), rare metal, from acid-leaching solution of Nd magnet. In this study, $FeCl_3$ solution as iron source was used for preparation of iron nano particles with the condition of various factors, such as, reductant, and surfactant. $Na_4P_2O_7$ and Polyvinylpyrrolidone (PVP) as surfactants, $NaBH_4$ as reductant, and palladium chloride ($PdCl_2$) as a nucleation seed were used. Iron powder was analyzed by using XRD, SEM for measuring shape and size. Iron nano particles were prepared at the ratio of 1:5 (Fe (III) : $NaBH_4$). Size and shape of iron particles were round-form and 50 ~ 100 nm size. Zeta-potential of iron at the 100 mg/L of $Na_4P_2O_7$ was negative value, which was good for dispersion of metal particle. When $Na_4P_2O_7$ (100 mg/L), PVP($FeCl_3:PVP$ = 1 : 4, w/w) and Pd($FeCl_3:PdCl_2$ = 1 : 0.001, w/w) were used, iron nano particles which were round-shape, well-dispersed and near 100 nm-sized range. In this condition, $FeCl_3$ solution changed with spent Nd leachate solution, and then it is possible to be made round-formed iron nano particles at pH 9 and at the reaction bath over 20 L which is not include any surfactant.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.73-73
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• 2018

최근 매실나무를 기주로 한 겨우살이의 인공재배에 성공함에 따라, 식품 소재로 이용하기 위해 일반성분을 분석하였다. 경기도 남양주시에서 매실나무를 기주로 한 인공재배 겨우살이를 채취하여 동결건조한 후 수분, 조단백질, 조지방, 회분, 탄수화물, 베타카로틴, 비타민 B1, 비타민 B2, 비타민 B3, 비타민C, Ca, Fe, K, Na 그리고 P의 함량을 분석하였다. 조단백질, 조지방, 회분, 베타카로틴, Ca, Fe, K, Na 그리고 P은 AOAC 방법을 이용하여 분석하였고, 탄수화물은 탄수화물(%) = 100 - (조단백질% + 조지방% + 회분% + 수분%) 계산식을 활용하여 산출하였다. 수분, 비타민 B1, 비타민 B2, 비타민 B3, 비타민 C는 식품공전에 제시된 방법에 따라 분석하였다. 동결건조한 매실나무겨우살이의 일반성분은 탄수화물 58.90%, 단백질 22.36%, 회분 11.11%, 지방 5.37%, 수분 2.26% 순으로 함유하였다. 비타민의 함량은 비타민 C 4.78mg/100g, 나이아신 1.87mg/100g, 비타민 A 1.42mg/100g, 비타민 B2 0.73mg/100g 그리고 비타민 B1 0.30 mg/100g의 순서로 많이 함유하였다. 무기질은 K 3141.54mg/100g, Ca 977.77mg/100g, P 309.91 mg/100g, Na 20.13mg/100g 그리고 Fe 8,24mg/100g의 순서로 많이 함유하였다.

• Journal of Environmental Health Sciences
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• v.21 no.2
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• pp.68-74
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• 1995

The optimum conditions was synthesized for the formation of Magnetite ($Fe_3O_4$) by air bubbling with the suspensions obtained by mixing Ferrous sulfate ($FeSO_4\cdot 7H_2O$) and Sodium Hydroxide (NaOH) solution in various values equivalent ratio($R=2NaOH/FeSO_4$) were studied. The changes of the structure were measured with XRD, $EM and BET. Equivalent ratio R: 0.65 was synthesized Goethite ($\alpha$-FeOOH), which becomes Maghemite ($\gamma=Fe_2O_3$) by dehydration, reduction and oxidation process. At the equivalent ratio over 1 (R>1), Magnetite ($Fe_3O_4$) was synthesized directly. The oxygen-deficient Magnetite ($Fe_3O_{4-\delta}$), which is obtained by flowing $H_2$ gas(100 ml/min) through the synthesis Magnetite at 350$\circ$C for 4 hr. By using it, was researched the decomposition reaction of $CO_2$. $CO_2$ was decomposed nearly 100% in 45 minutes by the oxygen-deficient Magnetite.