열처리에 따른 Y₂O₃박막의 미세 구조 변화와 전기적 특성 변화에 대한 고찰

정윤하(Y. H. Jung),강성관(S. K. Kang),김은하(E. H. Kim),고대홍(D. H. Ko),조만호(M. H. Cho),황정남(C. N. Whang) 한국진공학회(ASCT) 1999 Applied Science and Convergence Technology Vol.8 No.3(1)

p-type Si (100) 기판 위에 습식 산화법으로 SiO₂ 층을 형성한 후, Ionized Cluster Beam(ICB) 증착 방법으로 200 Å 두께의 Y₂O₃ 박막을 증착 하였다. Y₂O₃ 박막이 증착 된 시편을 산소, 아르곤 분위기에서 열처리한 후, Atomic Force Microscopy(AFM)과 Transmission Electron Microscopy(TEM)을 사용하여 Y₂O₃ 박막의 표면과 계면을 관찰하였다. 열처리를 수행한 후 Y₂O₃ 박막과 Si 기판 사이에서 SiO₂층이 성장하고, 이트륨실리 케이트 층이 형성되는 것을 관찰할 수 있었다. 산소 분위기에서 열처리를 수행한 시편의 Y₂O₃ 박막 표면을 관찰한 결과, 표면 상부에 아르곤 분위기에서 열처리한 시편에서는 보이지 않았던 새로운 상이 형성되었음을 알 수 있었다. 또한 전기적 특성을 측정하기 위하여 Al/Y₂O₃/p-type Si (100) 의 캐패시턴스-전압 특성을 관찰하였고, 그 결과 Y₂O₃ 박막의 유전 상수 값이 약 9정도임을 알 수 있었다. We investigated the interfacial reactions between the Y₂O₃ film deposited by ICB processing and p-type (100) Si substrates upon annealing treatments in O₂ and Ar gas ambients. We also investigated the evolution of surface morphology of ICB deposited Y₂O₃ films upon annealing treatments. We observed that the root-mean-square (RMS) value of surface roughness measured by AFM increased with annealing time at 800℃ in O₂ ambient, while the change of surface roughness was not observed in Ar ambient. We also found the growth of SiO₂ layer and the formation of yttrium silicate layer. From the capacitance values (C_(acc)) measured by C-V measurements, the relative dielectric constant of Y₂O₃ film in metal-insulator-semiconductor (MIS) structure was estimated to be about 9.

DMF effect on the morphology and the luminescence properties of Y₂O₃:Eu³⁺ red phosphor prepared by spray pyrolysis

Jung, K.Y.,Kang, Y.C.,Park, Y.K. Korean Society of Industrial and Engineering Chemi 2008 Journal of industrial and engineering chemistry Vol.14 No.2

N,N-Dimethylformamide (DMF) was used as a drying control chemical additive (DCCA) in spray pyrolysis in order to improve the luminous properties of Y<SUB>2</SUB>O<SUB>3</SUB>:Eu particles. It was found that the addition of DMF to the spray solution containing citric acid (CA) and ethylene glycol (EG) greatly enhances the photoluminescence intensity as well as the morphology of Y<SUB>2</SUB>O<SUB>3</SUB>:Eu particles. According to BET analysis, the surface area of Y<SUB>2</SUB>O<SUB>3</SUB>:Eu particles prepared from the solution containing only the organic additives was not reduced, whereas, the surface area of the Y<SUB>2</SUB>O<SUB>3</SUB>:Eu particles prepared from the solution containing both DMF and organic additives was decreased gradually as increasing the concentration of DMF. From these results, it was concluded that the adding of DMF to the spray solution containing the organic additives is a very effective way to reduce the porosity of phosphor particles, keeping the spherical morphology. As a result, the densification of porous structure led to greatly improve the photoluminescence intensity of Y<SUB>2</SUB>O<SUB>3</SUB>:Eu particles under ultraviolet (254nm) excitation. Finally, the prepared Y<SUB>2</SUB>O<SUB>3</SUB>:Eu particles with dense structure showed about 208% improved photoluminescence intensity compared with the particles which have a spherical shape but porous structure.

중년 남성의 갱년기 증상 유･무에 따른 가족관계와 건강증진행위 비교

강민형,김소영,김하은,안상아,양혜지,이예지,이유진,정수영,최윤영,최지윤,신수진,이민경 이화여자대학교 간호과학대학 2017 이화간호학회지 Vol.- No.51

Purpose: The purpose of this study was to examine the difference of family relationship and health promoting behaviors between two groups depending on presence and absence of climacteric symptoms among middle-aged male. Methods: Samples of 220 men aged between 40 and 64 were recruited from metropolitan areas. The subjects responded to self-report questionnaires on general characteristics, climacteric symptoms, family relationship and health promoting behaviors. Data was collected from September 13, 2016 to September 30, 2016 and analyzed by using t-test, Pearson's correlation efficient, -test, frequency and percentage analysis. Result: In general characteristics of subjects, according to the presence or absence of climacteric symptoms, there were significant differences in occupation( =12.12, p=0.02), average monthly incom ( =11.01, p=0.01), and physical condition( =12.07, p=0.02). Mean scores of family relationship(t=-2.784, p=.008) and health promotion behaviors(t=3.629, p=.000) were significantly higher in climacteric symptom group. Significant positive correlation appeared between family relationship and health promoting behaviors in both presence(r=.493, p=.000) and absence group(r=.698, p=.000). But climacteric symptoms were in negative correlation with family relationship(r=-.187, p=.018) and health promoting behavior(r=-.233, p=.002) only in presence group. Conclusion: This study suggests that family relationship and health promoting behaviors should be considered in developing nursing intervention for climacteric middle–aged males.

Co-Y 비정질 박막합금의 자기적 성질

강일구,김희중,한석희,이정중,김광윤 대한금속재료학회(대한금속학회) 1990 대한금속·재료학회지 Vol.28 No.11

The magnetic properties of amorphous Co-Y thin films prepared by RF magnetron sputtering have been investigated. The saturation magnetization of Co-Y alloy is linearly decreased with increasing Y content, and the magnetic moments of Co-Y alloys larger than those of Friedel's theory were interpreted by the atomic size effect. The coercive force is drastically decreased at about 8 at.% Y which is the minimum solute concentration to get the amorphous phase. The solute concentration of film is monotonously increased with increasing Ar pressure, and the coercive force shows the lowest values at the Ar pressure of 5 mTorr. Effective permeability in hard direction of thin film produced in magnetic field is lower at low Frequencies but higher at high frequencies above 100 ㎑ than those of easy direction. The rotating magnetic field annealing is effective to increase the effective permeability at overall frequency range.

여자 대학생의 저출산에 대한 인식 : 서울 지역 중심으로

김연주,김주예,김혜,민지유,박현영,이송,이혜심,주연진,최지희,함연화,강숙정,김부연,김윤정 이화여자대학교 간호과학대학 2019 이화간호학회지 Vol.- No.53

Purpose: The purpose of this study is to understand the perception of low birth rate within female college students. Methods: After obtaining approval from online community and several acquaintance, data were collected from August 10 to September 11. A total of eight students participated in the study. Semi-structured in-depth interview were conducted and the data subsequently analyzed. Results: This study extracted three themes: Fragmentary perception about low birth rate limited to social level problem; Avoidance about sacrifice from delivery and Lack of effectiveness in fertility incentives of present government. Conclusion: This study is meaningful that can explore the perception about low birth rates of female college students who are the subjects of future birth. They recognize low birth rates as a social problem, but do not recognize as individual problem. In addition, this study was able to identify the participants' perception of the low birth rate. It can be suggested as meaningful opinion for some follow-up study.

고분자 전구체 용액으로부터 분무열분해법에 의해 합성되어진 구형 형상의 Y₂SiO₅:Ce 형광체

강희상,강윤찬,박희동,설용건,Kang, H.S.,Kang, Y.C.,Park, H.D.,Shul, Y.G. 한국재료학회 2003 한국재료학회지 Vol.13 No.3

Ce-doped $Y_2$SiO$_{5}$ phosphor particles of spherical morphology, fine size, high crystallinity and high photoluminescence (PL) intensity were prepared by spray pyrolysis. When nitrate precursor solution is adopted, hollow particles were formed by uneven drying rate between surface and inside of droplet. Citric acid and ethylene glycol were introduced as polymeric precursor to control the morphology of particles. When polymeric solution is adopted, polymeric chain is formed by the esterification reaction between carboxyl and hydroxy groups of citric acid and ethylene glycol, and considered as controlling the drying characteristics of droplet. $Y_2$$SiO_{5}$ :Ce phosphor particles prepared from polymeric precursor solution were spherical, filled, fine size and not agglomerate before and after post heat treatment. The optimum doping concentration of cerium was 0.5 mol% of overall solution concentration. The optimum amount of TBOS of high PL intensity and pure crystallinity of X2-type $Y_2$$SiO _{5}$ was 105% of stoichiometric amount. The PL intensity of $Y_2$X$/_{5}$ :Ce phosphor particles prepared using the polymeric precursor solution was 164% of that of the nitrate precursor solution due to homogeneous composition and good morphology.y.

Synthesis of characterization of Zn_xTi_yS and its photocatalytic activity for hydrogen production from methanol/water photo-splitting

Lee, H.,Park, Y.,Kang, M. Korean Society of Industrial and Engineering Chemi 2013 Journal of industrial and engineering chemistry Vol.19 No.4

In order to enhance the production of hydrogen, a new system based on a Zn<SUB>x</SUB>Ti<SUB>y</SUB>S photocatalyst is investigated. Zn<SUB>x</SUB>Ti<SUB>y</SUB>S (x=1, 0.95, 0.9, 0.85, 0.8mol and y=0, 0.05, 0.1, 0.15, 0.2mol, respectively) is prepared using thiourea (H<SUB>2</SUB>NCSNH<SUB>2</SUB>). The formed Zn<SUB>x</SUB>Ti<SUB>y</SUB>S particles are globular, ~6μm in diameter, and composed of small spherical particles about 600nm in diameter. The Zn<SUB>x</SUB>Ti<SUB>y</SUB>S particles absorb at wavelengths above 380nm in the UV-region like TiO<SUB>2</SUB>. The evolution of H<SUB>2</SUB> by methanol/water (1:1) photo-splitting over Zn<SUB>x</SUB>Ti<SUB>y</SUB>S in a methanol/water system is dramatically enhanced versus pure ZnS. In particular, 4.0mmol of H<SUB>2</SUB> gas is produced in 10h when 1.0g of Zn<SUB>0.9</SUB>Ti<SUB>0.1</SUB>S was used, and its performance increases in KOH solutions. Based on cyclic voltammetry (CV) and UV-vis spectroscopy measurements, the high photo-activity of Zn<SUB>0.9</SUB>Ti<SUB>0.1</SUB>S is attributed to the existence of a band-gap that includes the redox potential of water.

노인의 병원 선택 경험

김단비,김민지,김해솔,김희정,박윤선,손유경,송예진,유예림,이다예,이서영,이지현,강숙정,김부연 이화여자대학교간호학회 2020 이화간호학회지 Vol.- No.54

Purpose: The purpose of this descriptive study was to examine hospital choice factors among elderly patients to understand their experience and use as data to move towards senior-friendly hospitals. Methods: The individual in-depth interviews were conducted from August 13th to 18th, 2019. The participants consisted of eight senior citizens aged 65 and above that suffered from chronic illnesses and had regular hospital visits. Results: This study found that when elderly patients choose the hospital, they considered ‘awareness such as brand name of the hospital', ‘quality of medical service',‘convenience', ‘healthcare team / hospital employee', ‘personal experience', ‘children’s recommendation’ and etc,. The significant point was that all these factors were related to personal experiences from specific hospitals. Conclusion: This study analyzed the hospital choice factors of the elderly patients with high hospital utilization rates and found that the results were mainly affected by the distinct characteristics of elderly patients. The implications of this study are that we proposed further research directions and means for the improvement of the hospital. We suggest hospitals to increase labor allocation for elderly patients with difficulties dealing with unmanned systems such as kiosk and strengthen the role of healthcare providers as instructors for higher satisfaction.

Na₂O·B₂O₃·V₂O_(5) 반도체 유리의 유전성질에 관한 연구

강재필,차유정,김영훈,홍성덕,서용문,송승기 명지대학교 자연과학연구소 2006 자연과학논문집 Vol.25 No.-

Na_(2)O·B_(2)O_(3)·V_(2)O_(5) 반도체 유리를 다양한 성분비로 제작하여 시료에 관한 유전상수와 유전손실의 주파수(0.1~100 kHz)와 온도(125~325K)의존성을 연구했다. ε_(real)과 ε_(imag)은 주파수를 증가시키면 천천히 감소했으며, ε_(img)는 유리 안에 도입되는 V_(2)O_(5) 양이 많을수록 감소함이 컸다. 유전상수와 유전손실은 온도를 증가시키면 약 300K까지는 서서히 변화하였으나 그 이상의 온도에서는 급격히 증가하였으며, 이들 유리에서 ε_(real)과 ε_(imag)의 온도의존성이 Debye형 유전이완을 따르고 있음을 보였다. The frequency (0.1~100 kHz) and temperature (125~325 K) dependent dielectric constant (ε_(real)) and dielectric loss (ε_(img)) have been investigated for the samples of various compositions in Na_(2)O·B_(2)O_(3)·V_(2)O_(5) semiconducting glasses. The ε_(real) and ε_(img) decrease slowly with increasing frequency, and the decrease of ε_(img) is sharper with the increase of V_(2)O_(5) content in the glasses. The dielectric constant and dielectric loss varies slowly with increasing temperature up to about 300 K and then the magnitude of these values increases sharply with further increase of temperature, which shows that the temperature dependence of ε_(real) and ε_(img) is Debye-type dielectric relaxation in these glasses.

한국 소재 대학교에 재학 중인 재외국민대학생의 문화지능과 학습참여도가 우울에 미치는 영향

강보미,강유빈,고미영,김찬송,남의정,박소은,박정연,백도윤,이혜린,한보혜,신주현,손지희 이화여자대학교 간호과학대학 2019 이화간호학회지 Vol.- No.53

Purpose: This study aims to identify the impact that cultural intelligence and learning engagement of Korean overseas students in Korea have in depression, also, to propose direction for further research, and to suggest a nursing intervention program that aims to the reduction of depression in overseas students. Methods:. The selected participants of the present study were Korean Overseas University Students enrolled in a special admission for overseas students. Data were obtained through the use of SPSS Window 25 and analyzed using descriptive statistics, t-test, ANOVA, Scheffe test, Pearsons correlation coefficient, and multiple linear regression analysis. Results: Depression in Korean overseas university students is influenced by the education system(ß=-.193, p=.046) and continent of residency(ß=0.197, p=.03). It is necessary to take into account the differences of education systems as well as the cultural differences from where they come from for the purpose of reducing depression rates in overseas Koreans. Conclusion: The results of this study show that depression in Korean overseas students is related to the differences in continents of residency and the education systems. Consequently, the development and implementation of a nursing intervention program considering both factors, the continent and education system, has become a necessity that relates to the reduction of depression in Korean overseas students.