SHS 공정에 의해 제조된 Mo_xW_1-xSi₂ 발열체의 열화메커니즘

이동원,이상헌,김용남,이성철,구상모,오종민,Lee, Dong-Won,Lee, Sang-Hun,Kim, Yong-Nam,Lee, Sung-Chul,Koo, Sang-Mo,Oh, Jong-Min 한국전기전자재료학회 2017 전기전자재료학회논문지 Vol.30 No.10

The degradation mechanism of $Mo_xW_{1-x}Si_2$ ultrahigh-temperature heating elements fabricated by self-propagating high-temperature synthesiswas investigated. The $Mo_xW_{1-x}Si_2$ specimens (with and without post-annealing) were subjected to ADTs (accelerated degradation tests) at temperatures up to $1,700^{\circ}C$ at heating rates of 3, 4, 5, 7, and $14^{\circ}C/min$. The surface loads of all the specimen heaters were increased with the increase in the target temperature. For the $Mo_xW_{1-x}Si_2$ specimens without annealing, many pores and secondary-phase particles were observed in the microstructure; the surface load increased to $23.9W/cm^2$ at $1,700^{\circ}C$, while the bending strength drastically reduced to 242 MPa. In contrast, the $Mo_xW_{1-x}Si_2$ specimens after post-annealing retained $single-Mo_xW_{1-x}Si_2$ phases and showed superior durability after the ADT. Consequently, it is thought that the formation of microcracks and coarse secondary phases during the ADT are the main causes for the degraded performance of the $Mo_xW_{1-x}Si_2$ heating elements without post-annealing.

Mo/SiO₂/Si(100)기판 위에 MOCVD법으로 성장시킨 AIN박막이용 GHz대역의 FBAR제작에 관한 연구

양충모,김성권,차재상,박구만,Yang, Chung-Mo,Kim, Seong-Kweon,Cha, Jae-Sang,Park, Ku-Man 한국조명전기설비학회 2006 조명·전기설비학회논문지 Vol.20 No.4

본 논문에서는 $Mo/SiO_2/Si(100)$ 기판 위에 MOCVD(Metal-Organic-Chemical-Vapor Deposition)법을 이용하여 C축 방향으로 성장시킨 AIN(Aluminum Nitride) 박막을 이용하여 GHz대역 무선 통신에서 사용할 수 있는 FBAR(Film-Bulk-Acoustic Resonator)을 제작하였다. 제작된 공진부의 공진주파수와 반공진주파수는 각각 3.189[GHz]와 3.224[GHz]으로 측정되었으며, Q값(Quality Factor)과 유효한 전기기계 결합계수(${k_{eff}}^2$)는 각각 24.7과 2.65[%]로 평가되었다. AIN의 증착(Deposition) 조건은 $950[^{\circ}C]$의 기판표면(Substrate) 온도, 20Torr의 압력, 25000의 N/Al의 V/III비로 증착하였다. $4{\times}10^{-5}[\Omega{cm}]$의 Mo 하부전극 고유저항과 $Mo/SiO_2/Si(100)$ 기판 위에 AIN(0002) FWHM(Full-Width at Half-Maximum) 4를 갖는 C축 방향성의 AIN 박막을 성공적으로 성장시켰다. 따라서 증착된 AIN박막의 FWHM값은 GHz대역 무선 통신용 RF(Radio Frequency) 밴드 패스 필터 설계에 유용하게 사용될 것이다. In this paper, it is reported that film-bulk-acoustic resonator with high c-axis oriented AIN film on $Mo/SiO_2/Si(100)$ using metal-organic-chemical-vapor deposition was fabricated. The resonant frequency and anti-resonant frequency of the fabricated resonator were observed with 3.189[GHz] and 3.224[GHz], respectively. The quality factor and the effective electromechanical coupling coefficient(${k_{eff}}^2$) were measured with 24.7 and 2.65[%], respectively. The conditions of AIN deposition were substrate temperature of $950[^{\circ}C]$, pressure of 20Torr, and V-III ratio of 25000. A high c-axis oriented AIN film with $4{\times}10^{-5}[\Omega{cm}]$ resistivity of Mo bottom electrode and $4[^{\circ}]$ of AIN(0002) full-width at half-maximum(FWHM) on $Mo/SiO_2/Si(100)$ was grown successfully. The FWHM value of deposited AIN film is useful for the RF band pass filter specification for GHz-band wireless local area network.

SHS 공정으로 제조된 Mo<SUB>x</SUB>W<SUB>1-x</SUB>Si₂ 발열체의 가속수명시험과 고장분석

이동원(Dong-Won Lee),이상헌(Sang-Hun Lee),김용남(Yong-Nam Kim),이희수(Heesoo Lee),이성철(Sung-Chul Lee),구상모(Sang-Mo Koo),오종민(Jong-Min Oh) 한국전기전자학회 2017 전기전자학회논문지 Vol.21 No.3

고온자전합성과 후열처리 공정으로 MoxW1-xSi₂ 발열체를 제조하였다. MoxW1-xSi₂ 발열체의 신뢰성을 검증하기 위해 가속수명시험을 수행하였으며, 수명시간을 Minitab 프로그램으로 추정하였다. 또한, 가속수명시험 후의 MoxW1-xSi₂ 발열체의 고장분석을 전기적과 구조적 특성으로부터 수행하였다. 그 결과, MoxW1-xSi₂ 발열체의 지배적인 고장 유형은 발열체 내부의 크랙 형성과 SiO₂ 보호층의 박리임을 확인하였다. MoxW1-xSi₂ heaters were fabricated by self-propagating high-temperature synthesis (SHS) process and post sintering process. To validate the reliability of the MoxW1-xSi₂ heaters, the accelerated life test (ALT) was conducted, and then lifetime to MoxW1-xSi₂ heaters was estimated by using Minitab programs. Also, the failure analysis of MoxW1-xSi₂ heaters after ALT was performed through electrical and structural properties. As the results, it was confirmed that the dominant failure mode of MoxW1-xSi₂ heaters is the crack formation in heaters and the delamination of protective SiO₂ layers.

Mo 화학기상증착에 있어서 불순물 농도에 미치는 증착조건의 영향

배상석,서성교,홍은식,김승모,조미정,한혜정,이두성,김세훈,민석홍 국립7개대학공동논문집간행위원회 2001 공업기술연구 Vol.1 No.-

The thermal decomposition process of Mo(CO)_6 on chemical vapor deposition was investigated by analyzing the effects of deposition temperature, pressure, and reaction gas on the phase change of deposited films. Mo_2C was deposited at or below 350℃ due to the incompleteness of thermal decomposition of Mo(CO)_6, but Mo films was successfully deposited at 400℃ or higher temperatures. The variation of deposition pressure did not change the dependence of decomposition process on deposition temperature. The activation energy of surface reaction was 5.8 ㎉/mole.

볼트장력으로 보강된 철근 콘크리트 기둥의 실험적 연구

김도훈,원학재,김성배,김상모,이창남,김상섭 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

As time goes up, structural capacity of members decreases in reinforced concrete structures. The deterioration of the capacity is mainly due to the corrosion of materials, poor construction and environmental pollution, etc. This deterioration is unavoidable, thus it is necessary to develop the method for repair and retrofit of structures in order to ensure structural safety of members. The purpose of this paper is to investigate the load-deflection, ultimate strength, failure mode, and energy absorption effect. For the test, the specimen size of column is 20cm×20cm×90cm reinforced with 4 number of main bars of 13mm diameter, tied bars of 6mm diameter. The test results show that the increasement of bolt and bolt tension's quantity improve the ultimate strength and energy absorption capacity.

A Study on the Magnetic Properties of Al-Doped Sulphur Spinel

Chin Mo Kim,Sam Jin Kim,Chul Sung Kim IEEE 2010 IEEE transactions on magnetics Vol.46 No.2

<P>FeCr<SUB>2-x</SUB>Al<SUB>x</SUB>S<SUB>4</SUB> ( x=0.1, 0.3, and 0.5) samples were prepared by solid state reaction method. The crystallographic structure and magnetic properties of the fabricated compounds were investigated by X-ray diffraction (XRD), superconducting quantum interference device (SQUID) magnetometer, and Mo¿ssbauer spectroscopy. The crystal structure is determined to be a cubic spinel with the space group of Fd-3m and the lattice constants <I>a</I> <SUB>0</SUB>= 9.998, 10.004, and 10.010 A¿ , respectively. The temperature dependence of magnetization, measured from 5 to 300 K, suggests that FeCr<SUB>2-x</SUB>Al<SUB>x</SUB>S<SUB>4</SUB> (x=0.1, 0.3, and 0.5) samples show ferrimagnetic behavior. The decrease of Ne¿el temperature compared with FeCr<SUB>2</SUB>S<SUB>4</SUB> could be interpreted by weakening of the exchange interaction by substitution of nonmagnetic Al ions. Mo¿ssbauer spectra of FeCr<SUB>2-x</SUB>Al<SUB>x</SUB>S<SUB>4</SUB> ( x= 0.1, 0.3, and 0.5) were obtained at various temperatures ranging from 4.2 to 300 K. Isomer shift values of the samples at various temperatures for FeCr<SUB>2-x</SUB>Al<SUB>x</SUB>S<SUB>4</SUB> (x=0.1 , 0.3, and 0.5) were 0.50 ¿ ¿ ¿ 0.73 mm/s, relative to the Fe metal, which are consistent with the Fe<SUP>2+</SUP> valence state.</P>

한의진단명과 진단요건의 표준화 연구 II (표준화 실례) : 2차년도 연구결과 중간 보고

양기상,최선미,최승훈,안규석,박경모,박종현,김성우,신승호,정우열,전병훈,고현,김정범,신상우,김성훈,김동희,권영규,엄현섭,장혜옥 한국한의학연구원 1996 한국한의학연구원논문집 Vol.2 No.1

The diagnostic requirements were suggested and explained regarding the systems of differentiation of symptoms and signs in the second year study of standardization and unification of the terms and conditions used for diagnosis in oriental medicine. The systems were as follows; - differential diagnosis according to condition of body fluid, differentiation of syndromes according to the state of qi and blood, differential diagnosis according to relative excessiveness or deficiency of yin and yang(氣血陰陽津液辨證) - differentiation of diseases according to pathological changes of the viscera and their interrelation - analyzing and differentiating of febrile diseases in accordance with the theory of the six channels(傷寒辨證) The individual diagnosis pattern was arranged by the diagnostic requirements in the following order : another name(異名), notion of diagnosis pattern, index of differentiation of symptoms and signs(辨證指標), the main point of diagnosis, analysis of diagnosis pattern(證候分析), discrimination of diagnosis pattern(證候鑑別), a way of curing a diseases(治法), prescription(處方), herb in common use(常用藥物), diseases appearing the diagnosis pattern(常見疾病), documents(文獻調査). This study was carried out on the basis of the Chinese documents and references.

감정의 절제를 통한 연애로의 비약과 『동아일보』 연재소설의 방향성 -『 너희들은 무엇을 어덧느냐 』를 중심으로-

김상모(Kim, Sang-mo) 한국언어문학회 2018 한국언어문학 Vol.107 No.-

In this study, I consider Yeom Sang-sub’s What did you get in point of a serial novel.What did you get is Dong-A Ilbo’s serial novel, so it has continuity and differentiation of Dong-A Ilbo’s other serial novel. Continuity is that Dong - A Ilbo s discourse is revealed in the novel. In the growth novels and detective novels, Dong-A Ilbo revealed their worldview. Similarly, a romance novel makes a sacred love affair between people as its content. However, the novel contents reveal the difference. The character in the novel does not get the ability to love. In Donga Ilbo s love discourse, unrestrained emotions are eliminated as bad things. And love is considered sacred, so lovers should be a excellent person who can do divine love. After all, lovers should be able to contribute to society through their love. Emotions not leading to home and marriage were considered bad. The characters of What did you get are the same. They are faithful to their feelings, but the external gaze is critical. So they internalize the external gaze and critically see their emotions. The problem, then, they will not be able to make love. The external gaze is only focused on criticizing emotions, and it never raises the ability to make love. Consequently there is a crack between Dong-A Ilbo s discourse and romance novel’ content. Dong-A Ilbo tried to show the figure of personality person who can love. However, what was actually revealed was the inability of charater and the impossible of love. So it became clear that the romance novel is no longer suitable for the Dong-A Ilbo. Changes in the trends of the novel consisting of Dong-A Ilbo paper space innovation were influenced by these internal flow changes. Discourse no longer affects novels and is exposed to the it’s limit.

Site Preference for Fe in Zn-Doped Y-Type Barium Hexaferrite

Chin Mo Kim,Chan Hyuk Rhee,Chul Sung Kim IEEE 2012 IEEE transactions on magnetics Vol.48 No.11

<P>Polycrystalline Ba<SUB>2</SUB>Zn<SUB>x</SUB>Co<SUB>2-x</SUB>Fe<SUB>12</SUB>O<SUB>22</SUB> samples were prepared by solid state reaction method. The crystallographic structure and magnetic properties of the Zn-doped Y-type hexaferrite samples were investigated by X-ray diffraction, magnetization, and Mössbauer spectroscopy measurements. The crystal structure was found to be hexagonal with space group of <I>R</I>-3/<I>m</I>. The lattice constants of the samples increased as Zn contents increase. From the temperature dependence of magnetization, measured from 50 to 700 K, the magnetic transition temperature (<I>T</I><SUB>S</SUB>,<I>T</I><SUB>C</SUB>) of Ba<SUB>2</SUB>Zn<SUB>x</SUB>Co<SUB>2-x</SUB>Fe<SUB>12</SUB>O<SUB>22</SUB> decreased with increasing Zn concentration. Mössbauer spectra of Ba<SUB>2</SUB>Zn<SUB>x</SUB>Co<SUB>2-x</SUB>Fe<SUB>12</SUB>O<SUB>22</SUB>(x=0,1) were obtained at various temperature ranging from 4.2 to 300 K. Based on the observed spectra, the site occupancies in six interstitial sites of Co, Zn and Fe ions were calculated from the average of the relative sub-spectra absorption areas. Increasing Zn contents, the Debye temperature of the samples decreased. The isomer shift values of the samples at various temperatures were 0.1 <; δ <; 0.45mm/s, relative to the Fe metal, which were consistent with the Fe<SUP>3+</SUP> valance state.</P>

東川의 水環境 改善을 위한 洪水位 計算에 관한 연구

박상길,김성모,김상두,김가야 부산대학교 도시문제연구소 2001 都市硏究報 Vol.11 No.-

Public envirmental concern today is extendig to riverfronts as well. In this research, We have conducted on creating environmentally sound riverfronts that the public can use and enjoy, and which strike an ecological balance and are attractive to look at in the Dong-chun estuary. It is analysed flood with HEC-RAS program, for reconstruction with natural environmental landing treatment and automatic gate. It would be a basic data for better water environment in estuary.