• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1506-1508
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• 2010

$LiMnBO_3$ was successfully synthesized by a solid-state reaction method both with and without a carbon coating. Adipic acid was used as source material for the carbon coating. $LiMnBO_3$ was composed of many small polycrystalline particles with a size of about 50 - 70 nm, which showed a very even particle morphology and highly ordered crystalline particulates. Whereas the carbon coated $LiMnBO_3$ was well covered by mat-like, fine material consisting of amorphous carbon derived from the carbonization of adipic acid during the synthetic process. Carbon coated cell exhibited improved and stable discharge capacity profile over the untreated. Two cells delivered an initial discharge capacity of 111 and 58 mAh/g for $LiMnBO_3$/C and $LiMnBO_3$, respectively. Carbon coating on the surface of the $LiMnBO_3$ drastically improved discharge capacity due to the improved electric conductivity in the $LiMnBO_3$ material.

• Journal of the Korean Magnetics Society
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• v.11 no.6
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• pp.267-271
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• 2001

These experiments were carried out to examine the effects of elemental substitution of Mn and La-Mn on Sr-ferrite. The calcined properties for the Mn and La-Mn substitution were examined, and the sintered magnetic properties were compared with the stoichiometric condition. The magnetic properties of calcined SrM and (La-Mn)$_{0.3}$-SrM composition were as follows, respectively; M$_{s}$ : 61.06 emu/g, $_{i}$H$_{c}$ : 4.45 kOe and M$_{s}$ : 61.06 emu/g, $_{i}$H$_{c}$ : 4.46 kOe. Also, the sintered ferrite magnets of Mn$_{0.3}$-SrM and [(La-Mn)$_{0.3}$-SrM exhibited a similar properties to the stoichiometric composition but the coercivity of (La-Mn)$_{x}$-SrM was decreased rapidly with x=0.5.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.124-125
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• 2005

ZnS:Mn thin films have attracted great interest as electroluminescence devices. In this study, inductively coupled BCl$_3$/Ar plasma was used to etch ZnS:Mn thin films. We obtained the maximum etch rate of ZnS:Mn thin films was 2209 ${\AA}$/min at a BCl$_3$(20%)/Ar(80%) gas mixing ratio, an RF power of 700 W, a DC bias voltage of-250 V, a total gas flow of 20 sccm, and a chamber pressure of 1 Pa. It was proposed that sputter etching is dominant etching mechanism while the contribution of chemical reaction is relatively low due to low volatility of etching products.

• Journal of Food Hygiene and Safety
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• v.38 no.3
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• pp.170-175
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• 2023

In this study, the effect of MnSO₄ on the insecticidal crystal (IC) produced by Bacillus thuringiensis for a rapid detection medium was analyzed. The strains used included one B. thuringiensis reference (KCTC 1511) and nine wild-type strains. The IC in B. thuringiensis was detected following the method published by the Ministry of Food and Drug Safety in Korea. In the nutrient agar to which 0.005% MnSO₄ was added, IC was observed on two of the three plates after 48 hours of incubation and on all three plates after 120 hours. In AK agar, IC was observed on one and two of the three plates after 48 and 96 hours of incubation, respectively. These results indicated that 0.005% MnSO₄ nutrient agar is more appropriate than AK agar for production of IC in B. thuringiensis. The effect of various MnSO₄ concentrations on IC production was studied after 24 hours of incubation. IC was produced on 1 of the 10 plates with 0.000% MnSO₄ nutrient agar, 2 of the 10 plates with 0.001% MnSO₄ nutrient agar, and 3 of the 10 plates with 0.002% MnSO₄ nutrient agar. IC was not observed for the other nutrient agars containing 0.003%-0.009% MnSO₄. These results indicated that nutrient agar with 0.002% MnSO₄ led to the most rapid production of IC by B. thuringiensis after 24 hours of incubation. However, the conditions for IC production by B. thuringiensis depended on the incubation conditions and strain activity. Therefore, further studies are needed to verify the effects of 0.002% MnSO₄ on the production of IC by various Bacillus thuringiensis strains.

• Journal of Radiation Protection and Research
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• v.11 no.1
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• pp.70-76
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• 1986

In order to establish the national standards of neutron measurements, a manganese sulphate ($MnSO_4$) bath system was developed under the IAEA technical support. This bath system was made up of a spherical s.s. 316 L bath, of 3.5 mm thick and of 125 cm internal diagmeter, filled with a manganese sulphate solution, a solution circulating system, and a $^5Mn\;{\gamma}-ray$ monitoring system. The solution pumped from the bath was introduced into a Marinelli beaker-type monitor vessel which was equipped with two seperate detectors, $3.8cm{\phi}{\times}3.8cm$ NaI(T1) crystals. The performance of the system were tested using the neutron sources, $^{241}Am-Be\;and\;^{252}Cf$, mounted at the center of the bath. From the decay curve analysis of $^{56}Mn$ activity, neutron emission rate of $^{252}Cf$ by the comparative method was obtained to be $3.71{\times}10^7\;n/s\;per\;50{mu}g$ as of November 15, 1985.

• Resources Recycling
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• v.21 no.3
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• pp.21-27
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• 2012

In order to make high-purity ferro-manganese from $Mn_3O_4$ dust, the application of aluminothermy process to the reduction of $Mn_3O_4$ dust was investigated in previous work. The result showed the fact that can be obtained high purity ferro-manganese which have over about 93% of manganese content and lower impurities such as C, P, S than those of KS D3712 specification. The addition of silicon powder instead of aluminum powder was investigated as reductant in the thermite reaction process of $Mn_3O_4$ dust in this work because its production cost is lower than that of aluminum powder. In case of addition of silicon powder only as reductant, the experimental result showed the unstable ignition and no thermite reaction of mixture, but in case of simultaneous addition of silicon and aluminum powders as reductant, showed the fact that can be obtained high purity ferro-manganese which have much low content of impurities such as C, P, S component.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.71-75
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• 2005

$La_{0.5}Ca_{0.5}MnO_3$ colossal magnetoresistance (CMR) powders and pellets were synthesized by sol-gel process. The structural changes were investigated by FT-IR, CP/MAS $^{13}C$ solid state NMR spectroscopy and XRD. The particle characterization, microstructure of sintered samples, and cation composition of gel powders were studied by FE-SEM/EDS, TEM and ICP-AES. The structure refinement reveals that $La_{0.5}Ca_{0.5}MnO_3$ has orthorhombic, perovskite type unit cell. The magnetic characterizations were identified through measurement of magnetic moment by VSM.

• Korean Journal of Materials Research
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• v.17 no.9
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• pp.475-479
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• 2007

Pulsed laser deposition was utilized to grow MnS thin films on c-sapphire substrate using a KrF excimer laser at growth temperatures that ranged from room temperature to $700^{\circ}C$. The results of X-ray diffraction (XRD) and UV-visible spectroscopy were employed to investigate the structural and optical properties of the MnS films. While the growth rate decreased as $T_s$ increased, the overall quality of the film improved. The highest quality MnS film was obtained at $700^{\circ}C$. Variations in the $T_s$ resulted in the MnS films exhibiting different growth mechanisms. The oriented (200) rocksalt MnS film was grown at room temperature. In the case of higher $T_s,\;200{\sim}500^{\circ}C$, the films consisted of mixed phases of rocksalt and wurtzite. The main structure of the films was altered to (111) rocksalt when the temperature was increased to in excess of $600^{\circ}C$. This behavior may very well be the result of elements such as surface energy and atomic arrangement during the growth process. The optical band gap of the obtained ${\alpha}-MnS$ film was estimated to be 3.32 eV.

• Journal of the Korean Magnetics Society
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• v.13 no.5
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• pp.187-192
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• 2003

The magnetic and thermal properties of NiFe/[IrMn-Mn]/CoFe with Mn additions have been studied. As-deposited CoFe pinned layers with [IrMn-Mn]layer had dominantly larger exchange biasing field ( $H_{ex}$) and blocking temperature ( $T_{b}$) than those with pure I $r_{22}$M $n_{78}$ used. The $H_{ex}$ and $T_{b}$ improved with 76.8-78.1 vol% Mn, but those of the NiFe/IrMn/CoFe dropped considerably with more addition of 0.6 vol % Mn. The average x-ray diffraction peak ratios of fcc [(111)CoFe, NiFe]/(111)IrM $n_3$ textures for the Mn inserted total vol of 75.5, 77.5, and 79.3% were about 1.4, 0.8, and 0.6, respectively. For the sample without Mn inserted layer, the $H_{ex}$ between IrMn and CoFe layers was almost zero, but it increased to 100 Oe after annealing of 250 $^{\circ}C$. For as-grown two multilayers samples with ultra-thin Mn layers of 77.5 and 78.7 vol %, the $H_{ex}$s were 259 and 150 Oe, respectively. In case of IrMn with 77.5 vol% Mn, the $H_{ex}$ was increased up to 475 Oe at 350 $^{\circ}C$ but decreased to 200 Oe at 450 $^{\circ}C$, respectively. The magnetic properties and thermal stabilities of NiFe/[IrMn-Mn]/CoFe multilayer were enhanced with Mn additions. In applications where higher $H_{ex}$ and $T_{b}$ are required, proper contents of Mn can be used. be used. used.