• 한국전기전자재료학회논문지
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• 제29권6호
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• pp.365-369
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• 2016

In this paper, we fabricated Cu/Mn alloy shunt resistor with low resistance and thermal stability for use of mobile electronic devices. We designed metal alloy composed of copper (Cu) and manganese (Mn) to embody in low resistance and low TCR which are conflict each other. Cu allows high electrical conductivity and Mn serves thermal stability in this Cu/Mn alloy system. We confirmed the elemental composition of the designed metal alloy system by using energy dispersive X-ray (EDX) analysis. We obtained low resistance below $10m{\Omega}$ and low temperature coefficient of resistance (TCR) below $100ppm/^{\circ}C$ from the designed Cu/Mn alloy resistor. And in order to minimize resistance change caused by alternative frequency on circuit, shape design of the metal alloy wire is performed by rolling process. Finally, we conclude that design of the metal alloy system was successfully done by alloying Cu and 3 wt% of Mn, and the Cu/Mn alloy resistor has low resistance and thermal stability.

• 소성∙가공
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• 제9권1호
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• pp.66-71
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• 2000

The present study tackles the metallurgical subjects involving the thin slab-direct hot rolling process, i.e. mini-mill process. In order to clarify the effect of chemical composition of steel and MnS precipitation behaviors on the development of edge cracking during hot rolling, the content of manganese and sulfur in low carbon steel was varied and the isothermal treatment prior to roughing was applied. Edge cracking during roughing in the hot-rolling process of mini-mill was effectively prevented by means of the isothermal treatment at 115$0^{\circ}C$ for 5 minutes in the 0.4% manganese steel containing sulfur lower than 0.013%. With the increase in manganese content in low carbon steel, coarser MnS developed. The edge cracking index which denotes the total length of edge crack per unit edge-length of rolled specimens was proposed in this paper. It was found that the edge cracking index linearly decreased with the increase in the ratio of MnS.

• 한국재료학회지
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• 제11권9호
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• pp.759-762
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• 2001

Mg$_2$SnO$_4$having an inverse spinel structure was selected as a new host material of $Mn^{2+}$ activator. The luminescence of the $Mg_2$SnO$_4$:Mn phosphor prepared by the solid-state reaction were investigated under ultraviolet and low-voltage electron excitation. The Mn-doped magnesium tin oxide exhibited strong green emission with the spectrum centered at 500nm wavelength. It was explained that the green emission in $Mg_2$SnO$_4$:Mn phosphor is due to energy transfer from $^4T_1to ^6A_1\;of\; Mn^{2+}$ ion at tetrahedral site in the spinel structure. The optimum concentration of $Mn^{2+}$/ion exhibiting maximum emission intensity by the low-voltage electron excitation was 0.6mol%. ？

• 한국표면공학회지
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• 제30권1호
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• pp.57-62
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• 1997

Green-emitting $ZnGa_2O_4$ : Mn phosphors were synthesized by a thermal method and their low-voltage cathodoluminescent characteristics were examined for the field emitter display (FED) application. Low efficiency of $ZnGa_2O_4$ : Mn phosphors could be ascribed to the low penetration depth of into phosphors, which might results in charge accumulation on the phosphors screen. For increasing cathodoluminescent of $ZnGa_2O_4$ : Mn under low voltage excitation, wide band-gap oxide materials were added to the $ZnGa_2O_4$: Mn powder. It is found that the luminance can be increased by 20%. Measurement of leakage current on the phosphor screen shows that the enhancement of low-voltage cathodoluminescent by additive materials is mainly due to the consumption of surface charges on the phosphor.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.815-818
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• 2002

Mn doped hexagonal phase of ZnS has been studied as a yellow-orange phosphor for the application to fluorescent displays operated at low voltages. It was found that luminescence from $Mn^{2+}$ was increased as the Mn concentration was increased up to1.2 mol% of host lattice. This study has been attempted by adding trivalent ions such as $Al^{3+}$ or $Bi^{3+}$ to ZnS:Mn as an agent to do the efficient incorporation of Mn ions into ZnS:Mn lattice, resulting in a significant improvement in the phosphor performance, especially at low voltages.

• 한국전기전자재료학회논문지
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• 제30권6호
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• pp.376-380
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• 2017

In this paper, we prepared a metal alloy resistor with stable thermal electro motive force (thermal EMF) as well as a low temperature coefficient of resistance (TCR) by adjusting the manganese proportion from 3 to 12 wt% in the Cu-Mn-Ni alloy. Composition of the fabricated metal alloy was investigated using energy dispersive X-ray (EDX) analysis. The TCR of each sample was measured as 44.56, 40.54, 35.60, and 31.56 ppm for Cu-3Mn-2Ni, Cu-5Mn-2Ni, Cu-10Mn-2Ni, and Cu-12Mn-2Ni, respectively. All the resistor samples were available for the F grade (${\pm}1%$ of the allowable error of resistance) high-precision resistor. All the samples satisfied the baseline of high thermal EMF (under 3 mV at $60^{\circ}C$); however, Cu-3Mn-2Ni and Cu-5Mn-2Ni satisfied the baseline of low thermal EMF (under 0.3 mV at $25^{\circ}C$). We were thus able to design and fabricate the metal alloy resistor of Cu-3Mn-2Ni and Cu-5Mn-2Ni to have low TCR and stable thermal EMF at the same time.

• Applied Microscopy
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• 제48권4호
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• pp.117-121
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• 2018

The multiple length scale analysis of previously designed Fe-Mn-Al-C based low-density model alloys reveals the difference in ordered ${\kappa}-carbide$, $(Fe,Mn)_3AlC_x$, between Fe-25Mn-16Al-5.2C (at%) alloy and Fe-3Mn-10Al-1.2C (at%) alloy. For the former alloy composition consisting of fully austenite grains, ${\kappa}-carbide$ showed majorly cuboidal and minorly pancake morphology and its chemical composition was not changed through aging for 24 h and 168 h at $600^{\circ}C$. Meanwhile, for the isothermally annealed ferritic alloy system for 1 hr at 500 and $600^{\circ}C$, the dramatic change in the chemical composition of needle-shape ${\kappa}-carbide$, $(Fe,Mn)_3(Fe,Al)C_x$, was found. Here we address that the compositional fluctuations in the vicinity of the carbides are significantly controlled by abutting phase, either austenite or ferrite. Namely, the cooperative ordering of carbon and Al is an important factor contributing to carbide formation in the high-Mn and high-Al alloyed austenitic steel, while the carbon and Mn for the low-Mn and high Al alloyed ferritic steel.

• 공업화학
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• 제23권2호
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• pp.190-194
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• 2012

다양한 상용 $TiO_2$ 담체를 이용한 10 wt%의 Mn계 촉매를 습윤함침법으로 제조하여 $NH_3$에 의한 NO의 저온 선택적 촉매환원법(SCR) 반응 특성을 연구하였다. 촉매의 특성은 BET, XRD, XPS 그리고 TPR과 같은 물리화학적 분석을 통해 수행되었다. MnOx/$TiO_2$ 촉매의 MnOx 표면밀도는 비표면적에 영향을 받는다. 고분산된 망간산화물에 의한 낮은 MnOx surface density로 저온 SCR 활성이 증가하고 망간산화물의 $MnO_2$에서 $Mn_2O_3$로 환원되는 온도가 감소되었다. 우수한 SCR활성을 위해서는 망간산화물을 높은 비표면적을 가진 $TiO_2$에 담지되어야 하고 고분산된 비정질종이 존재해야 한다.

• Journal of Magnetics
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• 제11권4호
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• pp.164-166
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• 2006

We have investigated the dielectric and magnetic properties of ferroelectric-antiferromagnetic $BaTiO_{3}-LaMnO_{3}$ composite with changing relative mole percents. Due to high sintering temperature, i.e. $1150^{\circ}C$, the Ba ion in $BaTiO_{3}$ seems to diffuse into $LaMnO_{3}$; resulting in $BaTiO_{3}-(La,Ba)MnO_{3}$ ferroelectric-ferromagnetic composite. At room temperature, $0.9BaTiO_{3}-0.1LaMnO_{3}$ composite exhibits considerable magnetization (${\sim}0.7\;emu/g\;at\;2000\;Oe$) and low coercive field (${\sim}5\;Oe$). Also it exhibits high dielectric constant (${\sim}560$) and low loss (${\sim}0.08$) at 10 kHz. This result may imply that $BaTiO_{3}-LaMnO_{3}$ could be suitable for a low leakage multiferroic composite.

• 조명전기설비학회논문지
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• 제24권4호
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• pp.10-16
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• 2010

본 논문에서는 ZnO와 $Ga_2O_3$ 분말을 1 : 1의 mole비로 혼합하고 여기에 Mn을 첨가하여 Ar 주입 상태와 진공 상태에서 조성된 $ZnGa_2O_4$ : Mn을 합성하였다. 제작된 $ZnGa_2O_4$ : Mn의 발광 스펙트럼 관찰을 하여 산소의 성분 변화가 발광 특성에 미치는 영향을 설명하였다. 또한 저온의 Photoluminescence(PL) 스펙트럼으로부터 Mn의 site symmetry가 발광 스펙트럼에 미치는 영향을 설명하였다.