• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.7-10
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• 2001

Orthorhombic type $LiCo_{x}Mn_{1-x}O_{2}$(0 ${\times}$ 0.14) oxides have been synthesized by hydrothermal treatment of $(Co_{x}Mn_{1-x})_{3}O_{4}$ precursors and LiOH aqueous solution at $170^{\circ}C$. As-synthesized powders showed well-ordered ${\beta}-NaMnO_{2}$ structures, and the products were single crystalline particle oxides from TEM observations. The particle size decreased with increasing the amount of Co substituent. Much more improved capacity upon 100 cyclings was clearly seen in orthorhombic $LiCo_{0.1}Mn_{0.9}O_{2}$, comparing to orthorhombic $LiMnO_2$.

• Electrical & Electronic Materials
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• v.14 no.12
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• pp.7-10
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• 2001

Orthorhombic type LiCo$_{x}$Mn$_{1-x}$ O$_2$(0$\leq$x$\leq$0.14) oxides have been synthesized by hydrothermal treatment of (Co$_{x}$Mn$_{1-x}$ )$_3$O$_4$precursors and LiOH aqueous solution at 17$0^{\circ}C$. As-synthesized powders showed well-ordered $\beta$-MaMnO$_2$structures, and the products were single crystalline particle oxides from TEM observations. The particle size decreased with increasing the amount of Co substituent. Much more improved capacity upon 100 cyclings was clearly seen in orthorhombic LiCo$_{0.1}$Mn$_{0.9}$O$_2$, comparing to orthorhombic LiMnO$_2$./TEX>.EX>.

• Korean Journal of Crystallography
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• v.14 no.1
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• pp.13-15
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• 2003

For all primitive centric space groups in the triclinic, monoclinic and orthorhombic systems, either phase 0 or π can be allocated to three different kinds of reflections in order to specify the origin at one of the eight centers of symmetry. and the same holds for all primitive acentric space groups belonging to the point group 222. If these phased reflections are used as a basic set, more and more phased reflections with better accuracy could emerge in the process of direct methods.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.7-10
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• 2001

Orthorhombic type $LiCo_{x}Mn_{1-x}O_2$ (0 x 0.14) oxides have been synthesized by hydrothermal treatment of ($Co_{x}Mn_{1-x}$)$_3O_4$ precursors and LiOH aqueous solution at $170^{\circ}C$. As-synthesized powders showed well-ordered ${\beta}$-$NaMnO_2$ structures, and the products were single crystalline particle oxides from TEM observations. The particle size decreased with increasing the amount of Co substituent. Much more improved capacity upon 100 cyclings was clearly seen in orthorhombic $LiCo_{0.1}Mn_{0.9}O_2$, comparing to orthorhombic $LiMnO_2$.

• Bulletin of the Korean Chemical Society
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• v.6 no.4
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• pp.183-186
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• 1985

The lattice vibrational calculation of orthorhombic hydrogen chloride is performed using physically realistic potential function which can reproduce the X-ray structure and heat of sublimation of the low temperature phase. The polar coordinates representation is introduced in order to describe the intermolecular interactions in a molecular crystal. The splitting in internal modes is calculated as 49 $cm^{-1}$ and the other modes are in good agreement with experimental results.

• Applied Chemistry for Engineering
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• v.10 no.2
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• pp.231-236
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• 1999

Several series of morphologically controlled $MoO_3$/$SiO_2$ catalysts were prepared, characterized, and tested for hydrodesulfurization (HDS) of dibenzothiophene (DBT) activity. Molybdenum surface loaded with 4.0 atoms $Mo/nm^2$ was prepared as sintered hexagonal and sintered orthorhombic, as well as a novel "well dispersed hexagonal" phase. Characterization by XRD, Raman, and $O_2$ chemisorption results reveals that the dispersion of $MoO_3$ over silica depends on the final $MoO_3$ phase in the order of; sintered hexagonal < sintered orthorhombic < dispersed hexagonal phase. Temperature programmed reduction (TPR) results show that both bulk and dispersed microcrystalline of $MoO_3$ reduce to $MoO_2$ at $650^{\circ}C$ and to Mo metal at $1000^{\circ}C$. HDS of DBT was performed in a differential reactor at 30 atm over the temperature range $350{\sim}500^{\circ}C$. Activity of $MoO_3$/$SiO_2$ toward HDS of DBT is proportional to dispersion.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.6
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• pp.558-561
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• 2004

The morphology of silica supported $MoO_{3}$ catalysts, which was prepared by impregnation of ammonium heptamolybdate(AHM) with various surface loadings up to 4 atoms $Mo/nm^{2}$, was studied using x-ray diffraction(XRD). All morphologies of silica supported $MoO_{3}$ appear to be thermodynamically driven. For high loaded catalysts there appeared three states: a sintered and well-dispersed hexagonal state at moderate temperature calcination($300^{\circ}C$), and a sintered orthorhombic state at high temperature calcination($500^{\circ}C$). Whereas the sintered orthorhombic phase is detected by XRD at loadings in excess of 1.1 atom $Mo/nm^{2}$, the well-dispersed hexagonal phase is not detected even until 4.0 $atomsMo/nm^{2}$. The higher apparent dispersion of the hexagonal phase may arise from some role of ammonia which results in a stronger $MoO_{3}-SiO_{2}$ surface interaction.

• Journal of Powder Materials
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• v.8 no.2
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• pp.98-103
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• 2001

Metallic tin powder with diameter less than 50 nm was synthesized by inert gas condensation method and subsequently oxidized to tin oxide ($SnO_2$) along the two heat-treatment routes. The $SnO_2$ powder of single phase with a tetragonal structure was obtained by the heat-treatment route with intermediate annealing step-wise oxidation, whereas the $SnO_2$ powder with mixture of orthorhombic and tetragonal phases was obtained by the heat-treatment route without intermediate annealing (direct oxidation). $SnO_2$ gas sensors fabricated from the nano-phase $SnO_2$ powders were investigated by structural observations as well as measurement of electrical resistance. The $SnO_2$ gas sensors fabricated from the mixed-phase powder exhibited much lower sensitivity against $H_2$ gas than those fabricated from the powder of tetragonal phase. Reduced sensitivity of gas sensors with the new orthorhombic phase was attributed to detrimental effects of phase boundaries between orthorhombic and tetragonal phases and many twin boundaries on the charge mobility.

• Progress in Superconductivity
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• v.11 no.2
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• pp.141-146
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• 2010

Phase stability diagram and boundary of a- and c-axis orientation of $SmBa_2Cu_3O_{7-y}$ (SmBCO) thin films grown by pulsed laser deposition (PLD) were reported with studies based on x-ray diffraction [1]. Four different samples are systematically analyzed: normal c-axis oriented orthorhombic $SmBa_2Cu_3O_{7-y}$, a-axis oriented $SmBa_2Cu_3O_{7-y}$, c-axis oriented orthorhombic $SmBa_2Cu_3O_{7-y}$ with $Sm_2BaCuO_5$ phase, and a mixture with c-axis oriented orthorhombic $SmBa_2Cu_3O_{7-y}$ and anomalously long-c tetragonal $SmBa_2Cu_3O_x$. Raman scattering spectroscopy equipped with polarization analysis elucidates the crystal orientation and the origin of the growth of the materials. It indicates that the technique can be used for quality control of conductor manufacturing processes as well as for enhancement of the materials properties.

• Transactions on Electrical and Electronic Materials
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• v.7 no.2
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• pp.76-80
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• 2006

Well-defined orthorhombic $LiMnO_2\;and\;LiCo_{0.1}Mn_{0.9}O_2$ were synthesized by a solid-state reaction and quenching process. X-ray diffraction (XRD) results revealed that the as-synthesized powders showed an orthorhombic phase of a space group with Pmnm. The $Li/LiMnO_2\;and\;Li/LiCo_{0.1}Mn_{0.9}O_2$ cells were constituted and cycled galvanostatically in the voltage range of 2.0-4.3 V vs. $Li/Li^+$ at a current density of $0.5\;mA\;cm^{-2}$ at room temperature and $50^{\circ}C$, respectively. The results demonstrated that the highest specific capacity of $Li/LiMnO_2$ cells at room temperature and $50^{\circ}C$ was 95 and $155\;mAh\;g^{-1}$, respectively. As for $Li/LiCo_{0.1}Mn_{0.9}O_2$ cells, the highest specific capacity at room temperature and $50^{\circ}C$ was 160 and $250\;mAh\;g^{-l}$, respectively. It could be seen that the performance of $Li/LiCo_{0.1}Mn_{0.9}O_2$ cells was better than that of $Li/LiMnO_2$ cells.