http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Ln<sub>0.7</sub>Ca<sub>0.3</sub>MnO<sub>3</sub> (Ln=Nd, Sm, La)의 소결 거동 및 특성
전검배,구본흔,이찬규,Chon, Gom-Bai,Koo, Bon-Heun,Lee, Chan-Gyu 한국재료학회 2006 한국재료학회지 Vol.16 No.1
Effects of doping rare earth element on Ln site of $Ln_{0.7}Ca_{0.3}MnO_3$ (Ln=Nd, Sm and La) were examined from sintering behavior, structure and magnetic properties. Sintering reactions proceeded rapidly in order of $La_{0.7}Ca_{0.3}MnO_3>Nd_{0.7}Ca_{0.3}MnO_3>Sm_{0.7}Ca_{0.3}MnO_3$. This result can be explained by diffusivity of metal cation. Size of a-axis increased as following order of La<Nd<Sm, whereas c-axis was not much changed. Curie temperatures of 123K for $Nd_{0.7}Ca_{0.3}MnO_3$, 93K for $Sm_{0.7}Ca_{0.3}MnO_3$ and 225K for $La_{0.7}Ca_{0.3}MnO_3$ were obtained. This result coincides with change of Mn-O bond length causing by a-axis lattice constant.
Co/IrMn 이층막의 자기적 특성과 Co 두께 및 어닐링의 영향
정정규,이찬규,구본흔,이건환,야스노리하야시,Jung, Jung-Gyu,Lee, Chan-Gyu,Koo, Bon-Heun,Lee, Gun-Hwan,Hayashi, Yasunori 한국재료학회 2003 한국재료학회지 Vol.13 No.7
Effects of annealing and thickness of Co layer in Co/IrMn bilayers on the magnetic properties have been investigated. The highest interfacial exchange coupling energy($J_{K}$ = 0.12 erg/$\textrm{cm}^2$) was obtained for 10 nm Co layer thickness. Exchange bias field is inversely proportional to the magnetization, the thickness of the pinned layer, and the grain size of antiferromagnetic layer. Also it is related to the interfacial exchange energy difference, which is expected to depend on the surface roughness. These results almost agree with the random-field model of exchange anisotropy proposed by Malozemoff. Exchange bias field decreased slowly with increasing annealing temperature up to X$300^{\circ}C$. However, exchange bias field increased above $300^{\circ}C$.
전해 플라즈마 공정에 의해 AZ61A 합금에 형성된 산화물층의 특성에 미치는 OH<sup>-</sup> 이온 농도의 영향
신성훈,정영승,구본흔,Shin, Seong Hun,Jeong, Young Seung,Rehman, Zeeshan Ur,Koo, Bon Heun 한국재료학회 2016 한국재료학회지 Vol.26 No.10
The effect of NaOH concentration on the properties of electrolytic plasma processing (EPP) coating formed on AZ61A Mg alloy is studied. Various types of EPP were employed on magnesium alloy AZ61A in a silicate bath with different concentrations of NaOH additive. Analysis of the composition and structure of the coating layers was carried out using an X-ray diffractometer (XRD) and a scanning electron microscope (SEM). The results showed that the oxide coating layer mainly consisted of MgO and $Mg_2SiO_4$; its porosity and thickness were highly dependent on the NaOH concentration. The Vickers hardness was over 900 HV for all the coatings. The oxide layer with 3 g/l of NaOH concentration exhibited the highest hardness value (1220 HV) and the lowest wear rate. Potentiodynamic testing of the 3 g/l NaOH concentration showed that this concentration had the highest corrosion resistance value of $2.04{\times}10^5{\Omega}cm^2$; however, the corrosion current density value of $5.80{\times}10^{-7}A/cm^2$ was the lowest such value.
이순길,이화인,손진오,하광일,구본흔,Soon-Gil Lee,Hwa-In Lee,Jin-Oh Son,Gwang-Il Ha,Bon-Heun Koo 한국재료학회 2023 한국재료학회지 Vol.33 No.5
As a filler metal for lowering the melting point of Ag, many alloy metal candidates have emerged, such as cadmium, with zinc, manganese, nickel, and titanium as active metals. However, since cadmium is known to be harmful to the human body, Cd-free filler metals are now mainly used. Still, no study has been conducted comparing the characteristics of joints prepared with and without cadmium. In addition, studies have yet to be conducted comparing the typical characteristics of brazing filler metals with special structures, and the joint characteristics of brazing filler metals with available frames. In this study, the characteristics of junctions of silver-based intercalation metals were compared based on the type of filler metal additives, using a special structure, a filler metal sandwich structure, to protect the internal base metal. The general filler metal was compared using the structure, and the thickness of the filler metal according to the thickness was reached. A comparison of the characteristics of the junction was conducted to identify the characteristics of an intersection of silver-based brazing filler metal and the effect on joint strength. Each filler metal's collective tensile strength was measured, and the relationship between joint characteristics and tensile joint strength was explored. The junction was estimated through micro strength measurement, contact angle measurement with the base metal when the filler metal was melted, XRD image observation, composition analysis for each phase through SEM-EDS, and microstructure phase acquisition.
IrMn 교환결합층을 갖는 스핀밸브막에서의 열적안정성과 자구구조 관찰
이병선,정정규,이찬규,구본흔,야스노리 하야시,Lee Byeong-Seon,Jung Jung-Gyu,Lee Chang-Gyu,Koo Bon-Heun,Hayashi Yasunori 한국재료학회 2004 한국재료학회지 Vol.14 No.2
We have investigated the magnetic domain structure and the thermal stability of magnetotransport properties of IrMn biased spin-valves containing Co, CoFe and NiFe. The magnetic domain structures were imaged using a magneto-optical indicator film(MOIF) technique. To investigate the thermal stability, magnetoresistance(MR) was measured at annealing temperature(TANN) and room temperature($T_{RT}$) followed by the annealing. Domain imaging reveal that the increase of annealing temperature led to changes in the exchange coupling between the two ferromagnet(FM) layers through nonmagnetic layer rather than between FM and antiferromagnet. unlike the NiFe biased IrMn spin valve with large domains, MOIF pictures of Co and CoFe biased IrMn spin valve structures show the formation of many small microdomains. The magnetic structure, as revealed by the domain images, appeared unchanged while the MR dropped dramatically. From the combined giant magnetoresistance(GMR) and MOIF results, it was apparent that the decrease of MR ratio was not related to the spin valve magnetic structure up to about $350^{\circ}C$($T_{RT}$ ).
Ln<sub>0.7</sub>Ca<sub>0.3</sub>MnO<sub>3</sub>(Ln = Nd, Sm, La)의 자기적 전기적 특성
전검배,임흥수,이찬규,구본흔,이상민,정명화,조영훈,Chon, Gom-Bai,Im, Hung-Su,Lee, Chan-Gyu,Koo, Bon-Heun,Lee, Sang-Min,Jung, Myung-Hwa,Jo, Young-Hun 한국재료학회 2007 한국재료학회지 Vol.17 No.4
Effects of doping rare earth elements on Ln site of $Ln_{0.7}Ca_{0.3}MnO_3$ (Ln = N d, Sm and La) were examined from structure, magnetic and electrical properties. Size of a-axis increased as following order of La < Nd < Sm, whereas c-axis was not much changed. Curie temperatures of 170 K for $Nd_{0.7}Ca_{0.3}MnO_3$, 110 K for $Sm_{0.7}Ca_{0.3}MnO_3$ and 250 K for $La_{0.7}Ca_{0.3}MnO_3$ were obtained. This result coincides with change of Mn-O bond length causing by a-axis lattice constant. The highest magnetroresistance ratios were 22% at 77 K for $Sm_{0.7}Ca_{0.3}MnO_3$, 32% at 110 K for $Nd_{0.7}Ca_{0.3}MnO_3$, and 33% at 180 K for $La_{0.7}Ca_{0.3}MnO_3$.
Al<sup>3+</sup>와 Y<sup>3+</sup> 동시치환 SnO<sub>2</sub> 투명전극 박막의 전기적 특성
김근우,서용준,성창훈,박근영,조호제,허시내,구본흔,Kim, Geun-Woo,Seo, Yong-Jun,Sung, Chang-Hoon,Park, Keun-Young,Cho, Ho-Je,Heo, Si-Nae,Koo, Bon-Heun 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.10
Transparent conducting oxides (TCOs) have wide range of application areas in transparent electrode for display devices, Transparent coating for solar energy heat mirrors, and electromagnetic wave shield. $SnO_2$ is intrinsically an n-type semiconductor due to oxygen deficiencies and has a high energy-band gap more than 3.5 eV. It is known as a transparent conducting oxide because of its low resistivity of $10^{-3}{\Omega}{\cdot}cm$ and high transmittance over 90% in visible region. In this study, co-doping effects of Al and Y on the properties of $SnO_2$ were investigated. The addition of Y in $SnO_2$ was tried to create oxygen vacancies that increase the diffusivity of oxygen ions for the densification of $SnO_2$. The addition of Al was expected to increase the electron concentration. Once, we observed solubility limit of $SnO_2$ single-doped with Al and Y. $\{(x/2)Al_2O_3+(x/2)Y_2O_3\}-SnO_2$ was used for the source of Al and Y to prevent the evaporation of $Al_2O_3$ and for the charge compensation. And we observed the valence changes of aluminium oxide because generally reported of valence changes of aluminium oxide in Tin - Aluminium binary system. The electrical properties, solubility limit, densification and microstructure of $SnO_2$ co-doped with Al and Y will be discussed.
유전자 재조합 Human Growth Hormone 의 성장촉진 효과에 관한 연구
정요찬(Yo Chan Jeong),송동호(Dong Ho Song),조명행(Myung Haing Cho),구본흔(Bon Heun Koo),정광회(Kwang Hoe Chung),김경연(Kyeong Yeon Kim),정경환(Kyung Hwan Jung),이은경(Eun Kyung Lee),박두홍(Doo Hong Park) 한국응용약물학회 1995 Biomolecules & Therapeutics(구 응용약물학회지) Vol.3 No.3
The growth effects of newly developed recombinant human growth hormone (rHGH), were compared with those of Biotropine. For the effective evaluation, we examined the increasing rate of body weight and the thicknes of tibial epiphysis as criteria of growth effects on hypophysectomised female rats treated with varing concentration of rHGH for 4 days. rHGH treated groups showed significant body weight gain which was less evident in Biotropine and vehicle treatment group. In tibial epiphyseal test, rHGH also showed clear effects compared to Biotropine and vehicle treatment group. Above findings indicate that newly developed rHGH has better effects of growth stimulation on female rats than Biotropine does.