• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.497-502
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• 2019

Metal oxide nanostructures are promising materials for advanced applications, such as high sensitive gas sensors, and high capacitance lithium-ion batteries. In this study, tin oxide (SnO) nanostructures were grown on a Si wafer substrate using a two-zone horizontal furnace system for a various substrate temperatures. The raw material of tin dioxide ($SnO_2$) powder was vaporized at $1070^{\circ}C$ in an alumina crucible. High purity Ar gas, as a carrier gas, was flown with a flow rate of 1000 standard cubic centimeters per minute. The SnO nanostructures were grown on a Si substrate at $350{\sim}450^{\circ}C$ under 545 Pa for 30 minutes. The surface morphology of the as-grown SnO nanostructures on Si substrate was characterized by field-emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). Raman spectroscopy was used to confirm the phase of the as-grown SnO nanostructures. As the results, the as-grown tin oxide nanostructures exhibited a pure tin monoxide phase. As the substrate temperature was increased from $350^{\circ}C$ to $424^{\circ}C$, the thickness and grain size of the SnO nanostructures were increased. The SnO nanostructures grown at $450^{\circ}C$ exhibited complex polycrystalline structures, whereas the SnO nanostructures grown at $350^{\circ}C$ to $424^{\circ}C$ exhibited simple grain structures parallel to the substrate.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.1
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• pp.6-17
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• 1997

Lithium niobate single crystals with various [Li]/[Nb] ratios were grown by the Czochralski method from melts having compositions varing between 48.6 ~ 58.0 mol % $Li_2O$. A vapor transport equilibration technique has been used to improve the homogeneity and adjust the [Li]/[Nb] ratio in small $LiNbO_3$ single crystals grown by the Czochralski method. When equilibrated with a Li-rich powder (65 mol%$Li_2O$), containing a mixture of $LiNbO_3$ and $Li_3NbO_4$, crystals of nearly stoichiometric composition can be obtained. This was established by studying the composition dependence of the following properties; lineshape, intensity and linewidth for the electron paramagnetic resonance (EPR) of $Fe^{3+}$ energy of the fundamental absorption edge and $OH^-$ absorption spectra.