Cu 기판위에 성장한 MgO, MgAl₂O₄와 MgAl₂O₄/MgO 박막의 집속이온빔을 이용한 스퍼터링수율 측정과 이차전자방출계수 측정

정강원(K. W. Jung),이혜정(H. J. Lee),정원희(W. H. Jung),오현주(H. J. Oh),박철우(C. W. Park),최은하(E. H. Choi),서윤호(Y. H. Seo),강승언(S. O. Kang) 한국진공학회(ASCT) 2006 Applied Science and Convergence Technology Vol.15 No.4

MgAl₂O₄ 막은 MgO 보호막 보다 단단하며 수분 흡착 오염문제에 상당히 강한 특성을 가진다. 본 연구에서 AC-PDP의 유전체보호막으로 사용되는 MgO 보호막의 특성을 개선하기 위해 MgAl₂O₄/MgO 이중층 보호막을 제작하여 특성을 조사하였다. 전자빔 증착기를 사용하여 Cu 기판에 MgO와 MgAl₂O₄을 각각 1000 Å 두께로 증착, MgAl₂O₄/MgO을 200/800 Å 두께로 적층 증착 후, 이온빔에 의한 충전현상을 제거하기 위해 Al을 1000 Å 두께로 증착하였다. 집속 이온빔(focused ion beam ; FIB)장치를 이용하여 10 ㎸에서 14 ㎸까지 이온빔 에너지에 따라 MgO는 0.364 ~ 0.449 값의 스퍼터링 수율에서 MgAl₂O₄/MgO을 적층함으로 24 ~ 30 % 낮아진 0.244 ~ 0.357 값의 스퍼터링 수율이 측정되었으며, MgAl₂O₄는 가장 낮은 0.088 ~ 0.109 값의 스퍼터링 수율이 측정되었다. g-집속이온빔(g-FIB)장치를 이용하여 Ne? 이온 에너지를 50 V에서 200 V까지 변화 시켜 MgAl₂O₄/MgO와 MgO는 0.09 ~ 0.12의 비슷한 이차전자방출 계수를 측정 하였다. AC-PDP셀의 72시간 열화실험 후 SEM 및 AFM으로 열화된 보호막의 표면을 관찰하여 기존의 단일 MgO 보호막과 MgAl₂O₄/MgO의 적층보호막의 열화특성을 살펴보았다. It is known that MgAl₂O₄ has higher resistance to moisture than MgO, in humid ambient MgO is chemically unstable. It reacts very easily with moisture in the air. In this study, the characteristic of MgAl₂O₄ and MgAl₂O₄/MgO layers as dielectric protection layers for AC-PDP (Plasma Display Panel) have been investigated and analysed in comparison for conventional MgO layers. MgO and MgAl₂O₄ films both with a thickness of 1000 Å and MgAl₂O₄/MgO film with a thickness of 200/800 Å were grown on the Cu substrates using the electron beam evaporation. 1000 Å thick aluminium layers were deposited on the protective layes in order to avoid the charging effect of Ga? ion beam while the focused ion beam(FIB)is being used. We obtained sputtering yieds for the MgO, MgAl₂O₄ and MgAl₂O₄/MgO films using the FIB system. MgAl₂O₄/MgO protective layers have been found th show 24 ~ 30% lower sputtering yield values from 0.244 up to 0.357 than MgO layers with the values from 0.364 up to 0.449 for irradiated Ga? ion beam with energies ranged from 10 ㎸ to 14 ㎸. And MgAl₂O₄ layers have been found to show lowest sputtering yield values from 0.88 up to 0.109. Secondary electron emission coefficient(g) using the γ-FIB. MgAl₂O₄/MgO and MgO have been found to have similar g values from 0.09 up to 0.12 for indicated Ne+ ion with energies ranged from 50 V to 200 V. Observed images for the surfaces of MgO and MgAl₂O₄/MgO protective layers, after discharge degradation process for 72 hours by SEM and AFM. It is found that MgAl₂O₄/MgO protective layer has superior hardness and degradation resistance properties to MgO protective layer.

A study of nerve agent model organophosphonate binding with manganese-A₂B-corrole and -A₂B₂-porphyrin systems

Kim, K.,Kim, I.,Maiti, N.,Kwon, S.J.,Bucella, D.,Egorova, O.A.,Lee, Y.S.,Kwak, J.,Churchill, D.G. Pergamon Press 2009 Polyhedron Vol.28 No.12

Herein the synthesis and binding studies of novel trans-A<SUB>2</SUB>B-corrole and trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin derivatives are presented in comparing manganese(III)-organophosphonate (OP) binding (e.g., M<SUP>n+</SUP>←O?PR(OR)<SUB>2</SUB>) capabilities. H<SUB>3</SUB>(PFP-VC) [PFP-VC=5,15-di(pentafluorophenyl)-10-(3-vinylphenyl)corrolate] was synthesized by way of literature procedures and was characterized by a variety of 2-D NMR spectroscopic techniques and single-crystal X-ray diffraction. These compounds represent the first example of 3-vinyl-phenyl-containing meso-substituted corroles or porphyrins. Mn(PFP-VC) (3) was treated separately with (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(C<SUB>3</SUB>H<SUB>6</SUB>NMe<SUB>2</SUB>), (C<SUB>4</SUB>H<SUB>9</SUB>O)<SUB>2</SUB>P?O(Me), (C<SUB>2</SUB>H<SUB>5</SUB>O)<SUB>2</SUB>P?O(CH<SUB>2</SUB>COCH<SUB>3</SUB>), (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(Me), to give 1:1 adducts, as determined by UV-Vis spectroscopy (Job Plot), giving a red shift; Ph<SUB>3</SUB>P?O, was also found to bind, but very weakly. The trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin analogue Mn(PFP-VP) (4) was also prepared by way of a literature procedure; related binding studies gave 1:1 organophosphonate-Mn(PFP-VP) adducts (Job Plot). A clean blue shift occurred for the Mn-porphyrins at higher organophosphonate loadings (K<SUB>a</SUB> values: 6.7 (0.9)-11.9 (0.4)M<SUP>-1</SUP>). DFT geometry optimizations of O?P(OMe)<SUB>2</SUB>Me binding and formal Mn-O or P-O cleavage products in the unsubstituted neutral Mn-corrolato and -porphyrinato systems with a range of metal-based spin states revealed greatest stability in formal phosphoryl oxygen binding (energies: 11-13kcal/mol) for the Mn-corrole (singlet); the Mn-porphyrin (sextet) was also quite stable.

RF-O₂ Plasma 처리한 MgO 박막의 스퍼터링 수율 측정

정원희(W. H .Jeoung),정강원(K. W. Jeong),임연찬(Y. C. Lim),오현주(H. J. Oh),박철우(C. W. Park),최은하(E. H. Choi),서윤호(Y. H. Seo),김윤기(Y. K. Kim),강승언(S. O. Kang) 한국진공학회(ASCT) 2006 Applied Science and Convergence Technology Vol.15 No.3

RF-O₂ plasma 처리한 MgO 박막의 스퍼터링 수율을 집속이온빔 장치를 이용하여 측정하였다. 가속 전압 10 ㎸의 Ga 이온빔을 주사했을 때 plasma 처리하지 않은 MgO 박막의 스퍼터링 수율은 0.33 atoms/ion, RF-O₂ plasma 처리한 MgO 박막의 스퍼터링 수율은 0.20 atoms/ion 으로 RF-O₂ plasma 처리한 경우 스퍼터링 수율이 낮아졌다. 또한 XPS, AFM을 통해 plasma 처리로 인한 MgO 표면의 변화를 관찰하였다. MgO 박막에 RF-O₂ plasma 처리 한 후 XPS O 1s spectra의 binding energy와 FWHM 값이 각각 2.36 eV와 0.6167 eV 작아졌고 표면거칠기의 RMS 값 또한 0.32 ㎚ 작아졌다. We measured sputtering yield of RF O₂-plasma treated MgO protective layer for AC-PDP(plasma display panel) using a Focused Ion Beam System(FIB). A 10 ㎸ acceleration voltage was applied. The sputtering yield of the untreated sample and the treated sample were 0.33 atoms/ion and 0.20 atoms/ion, respectively. The influence of the plasma-treatment of MgO thin film was characterized by XPS and AFM analysis. We observed that the binding energy of the O 1s spectra, the FWHM of O 1s spectra and the RMS(root-mean-square) of surface roughness decreased to 2.36 eV, 0.6167 eV and 0.32 ㎚, respectively.

Preparation of magnetic activated carbon-chitosan nanocomposite for crystal violet adsorption

Ferda Civan Çavuşoğlu,Seher Akan,Ezgi Aleyna Arı,Ezgi Çetinkaya,Elif Çolak,Gamze Nur Daştan,Semina Deniz,Damla Erdem,Melda Köksal,Sevgi Korkmaz,Nursena Onsekiz,Betül Oruçoğlu,Didem Özkaya,Hamdi Buğra 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.11

Magnetic, cheap and versatile adsorbents were developed for crystal violet (CV) adsorption in this study. These adsorbents are magnetic activated carbon (AC-Fe3O4) and chitosan grafted magnetic activated carbon (Chitosan- AC-Fe3O4). Fe3O4 and chitosan were also used for adsorption. X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), zeta potential analysis and Fourier transform infrared spectroscopy (FTIR) methods were used for characterization of adsorbents. Adsorption parameters for CV were investigated. Raw chitosan and Fe3O4 were also used for CV adsorption to compare the results of composites. The chosen adsorption parameters are amount of adsorbent, contact time, initial CV concentration, and temperature. The equilibrium period was observed to be very short for chitosan and Fe3O4 nanoparticles. The adsorption efficiencies of these adsorbents are very low. AC-Fe3O4 and AC-Fe3O4-Chitosan nanoparticles reached equilibrium at 80min. The all adsorbent-CV systems followed pseudo second-order kinetic model. AC-Fe3O4 and AC-Fe3O4-Chitosan composites suited non-linear Freundlich isotherm for all temperatures (298, 308 and 318 K). Regeneration of adsorbents was also investigated. 1M of acetic acid and 0.1M of NaOH solutions were tested. Acetic acid solution desorbed CV better than NaOH solution at 6 hours.

Spark plasma sintering of UO2 fuel composite with Gd2O3 integral fuel burnable absorber

Papynov E.K.,Shichalin O.O.,Belov A.A.,Portnyagin A.S.,Buravlev I.Yu,Mayorov V.Yu,Sukhorada A.E.,Gridasova E.A.,Nomerovskiy A.D.,Glavinskaya V.O.,Tananaev I.G.,Sergienko V.I. 한국원자력학회 2020 Nuclear Engineering and Technology Vol.52 No.8

The paper studies spark plasma sintering (SPS) of industrially used UO2-based fuel containing integral fuel burnable absorber (IFBA) of neutrons Gd2O3. Densification dynamics of pristine UO2 powder and the one added with 2 and 8 wt% of Gd2O3 under ultrasonication in liquid has been studied under SPS conditions at 1050, 1250, and 1450 C. Effect of sintering temperature on phase composition as well as on O/U stoichiometry has been investigated for UO2 SPS ceramics. Sintering of uranium dioxide added with Gd2O3 yields solid solution (U,Gd)O2, which is isostructural to UO2. SEM with EDX and metallography were implemented to analyze the microstructure of the obtained UO2 ceramics and composite UO2- Gd2O3 one, particularly, open porosity, defects, and Gd2O3 distribution were studied. Microhardness, compressive strength and density were shown to reduce after addition of Gd2O3. Obtained results prove the hypothesis on formation of stable pores in the system of UO2-Gd2O3 due to Kirkendall effect that reduces sintering efficiency. The paper expands fundamental knowledge on pros and cons of fuel fabrication with IFBA using SPS technology.

MgAl₂O₄ 스피넬 내화물의 합성과 응용

이윤복,권상오,장윤식,박상희,오기동 부산대학교 1995 生産技術硏究所論文集 Vol.48 No.-

MgO-Al₂O₃계에서 MgO첨가량에 따른 스피넬의 생성과 소결성을 조사하였다. 아울러 스피넬 내화물과 시멘트를 구성하는 주성분인 CaO의 반응성에 대하여 검토하였다. 가열된 시편의 상은 대부분의 스피넬, 페리클레이스 및 코런덤으로 동정되었고 과잉의 MgO를 함유한 시편의 경우 1750℃에서는 잔류 코런덤은 확인되지 않았다. MgO 함량이 감소함에 따라 스피넬내에 Al₂O₃의 고용에 기인된 스피넬의 생산량은 증가하는 경향을 나타내었다. 과잉의 MgO를 함유한 시편은 1600℃에서 치밀화가 촉진되어 1750℃, 5시간 유지한 시편의 경우 최종 소결밀도는 3.51g/㎤였다. 1750℃, 5시간 유지한 시편을 회전침식시험한 결과, 과잉의 MgO를 함유한 시편의 경우 침식깊이가 8.2mm, 침식면적이 225㎟로 다른 시편에 비교하여 가동면에서 CaO에 대한 침식저항성이 우수하였다. Effects of MgO content in spinel formation and sintering behavior of MgO-Al₂O₃ system were investigated. The reactivity of CaO in spinel refractories was also studied. From phase analyse, the refractories composed of mainaly two phase as like periclase and spinel, and residual corundom. However, the residual corundum was almost disappeared as it was fired at 1750℃ with excess of MgO. As the amount of MgO was reduced, the formation of spinel increased due to solid solubility of Al₂O₃ in spinel. The sample with excess of MgO markedly promoted the densification of spinel at 1600℃. The density of sample fired at 1750℃ for 5h was 3.51g/㎤. In rotary corrosion test, the sample with excess of MgO content, which had 8.2mm in the corrosion depth and 225㎟ in the corrosion area showed excellent corrosion resistance against the reactivity of CaO on the surface of spinel refractories.

CHF₃ / C₂F6 플라즈마에 의한 실리콘 표면 잔류막의 특성

권광호(K.-H. Kwon),박형호(H.-H. Park),이수민(S. M. Lee),강성준(S. J. Kang),권오준(O.-J. Kwon),김보우(B.W. Kim),성영권(Y.-K. Sung) 한국진공학회(ASCT) 1992 Applied Science and Convergence Technology Vol.1 No.1

실리콘을 CHF₃/C₂F_6 가스 플라즈마를 이용하여 식각하면 실리콘위에 탄소, 불소 및 산소로 이루어진 잔류막이 형성된다. 이 잔류막을 XPS로 분석한 결과 탄소는 C-Si, C-Si, C-C/H, C-CF_x(x≤3), C-F, C-F₂, C-F₃ 결합을 하고 있으며, 불소는 F-Si, F-C 및 F-O 결합으로 이루어져 있음을 알았다. 한편 산소는 O-Si 및 O-F 결합으로, 실리콘은 Si-Si, Si-C 및 Si-O 결합상태를 나타낸다. 잔류막의 수직분포 연구를 통하여 Si-O 및 Si-C 결합이 탄소와 불소의 결합층 아래에 존재하고, 잔류막의 표면부에 F-O 결합이 분포함을 알았다. 또한 건식식각 변수가 잔류막 형성에 미치는 영향이 조사되었으며 CHF₃/C₂F_6 가스 유량비, RF power 벚 압력 등이 잔류막의 두께, 조성비 및 잔류막의 결합상태에 영향을 미침을 알 수 있었다. Si surfaces exposed to CHF₃/C₂F_6 gas plasmas in reactive ion etching (RIE) have been characterized by X-ray photoelectron spectroscopy (XPS). CHF₃/C₂F_6 gas plasma exposure of Si surface leads to the deposition of residual film containing carbon and fluorine. The narrow scan spectra of C 1s show various bonding states of carbon as C-Si, C-Si, C-C/H, C-CF_x(x≤3), C-F, C-F₂, and C-F₃. The chemical bonding states of fluorine are described with F-Si, F-C, and F-O. And the oxygen and silicon are also detected. The effects of parameters for reactive ion etching as CHF₃/C₂F_6 gas ratio, RF power, and pressure are investigated.

抗生物質의 製劑學的 硏究(Ⅴ) : Al. stearate와 Eudragit함량에 따른 Eudragit-암피실린 마이크로캅셀의 제조에 대한 연구 Studies on effect of Al.stearate and Eudragit contents in preparation of Eudragit-ampicillin microcapsules

김기경,김인규,김도훈,윤미옥,장정윤,김영림,최선옥,이경희,정기선,김종국 국립보건연구원 1994 국립보건원보 Vol.31 No.2

CoFeHfO 박막의 자기적 특성

이광은(K. E. Lee),느반더(L. V. Tho),김상훈(S. H. Kim),김철기(C. G. Kim),김종오(C. O. Kim) 한국자기학회 2006 韓國磁氣學會誌 Vol.16 No.4

Amorphous alloys of Co-rich magnetic amorphous films are well known as typical soft magnetic alloys. They are used for many kinds of electric and electronic parts such as magnetic recording heads, transformers and inductors. CoFeHfO thin films were prepared by RF magnetron reactive sputtering. The films were deposited onto Si(100) substrates with a power of 300W at room temperature. The reactive gas was introduced up to 10% (O₂/(Ar + O₂)) during deposition, and the Co<SUB>39</SUB>Fe<SUB>34</SUB>Hf<SUB>9.5</SUB>O<SUB>17.5</SUB> thin film exhibit excellent soft magnetic properties : saturation magnetization (4πM<SUB>s</SUB>) of 19 kG, magnetic coercivity (H<SUB>c</SUB>) of 0.37 Oe, anisotropy field (H<SUB>k</SUB>) of 48.62 Oe, and an electrical property is also shown to be as high as 300 μΩcm. It is assumed that the good soft magnetic properties of Co<SUB>39</SUB>Fe<SUB>34</SUB>Hf<SUB>9.5</SUB>O<SUB>17.5</SUB> thin film results from high electrical resistivity and large anisotropy field.

장기 저장연료의 열안정성 및 연료접촉 고무오링의 수명예측 연구

정근우(K. W. Chung),홍진숙(J. S. Hong),김영운(Y. W. Kim),한정식(J. S. Han),정병훈(B. H. Jeong),권태수(T. S. Kwon),서동욱(D. O. Suh),성민준(M. J. Sung),권영일(Y. I. Kwon) 한국트라이볼로지학회 2018 한국윤활학회지(윤활학회지) Vol.34 No.5

Thermal deterioration of fuel due to long-term storage influences engine performance and causes malfunctions. Fuel stability is usually evaluated via heat resistance and thermal stability during a brief heat shock at high temperature; storage stability in this scenario means that there is very little change in the quality of the fuel during long-term storage. In addition, rubber-based products such as oil seals, O-rings, and rubber hoses can influence the quality of the fuel. When these rubber products are in contact with fuel, they can swell, mechanically weaken, and occasionally crack, thus leaking low molar weight rubber and additives including plasticizer and antioxidant into the fuel to degrade its properties and shorten its useful lifetime. This study determines the thermal stabilities of three kinds of synthetic fuels by evaluating their low temperature kinematic viscosities, chemical composition changes via GC analyses, gross heat of combustion, and color changes. We evaluate the compression set of O-rings by immersing one NBR and two FKM rubber O-rings in the three synthetic fuel samples in airtight containers at variable storage temperatures for six months; from this, we estimate the lifetimes of the O-rings using the Power law model. There were very little changes in the chemical compositions and gross heat of combustion after six months of the experiment. The lifetimes are thus dependent on the materials of the rubber products, and in particular, the FKM O-ring was calculated to have a theoretical lifetime of 200 to 5,700 years. These results indicate that the synthetic fuels maintain their physical properties even after long-term storage at high temperatures, and the FKM O-ring is suitable for long-term sealing of these fuels.