Growth of Lithium Fluoride and Magnesium Oxide Whiskers in the Electron Microscope

Hulse, C. O.; Tice, W. K.

doi:10.1038/206079a0

Cited by 12 publications

(5 citation statements)

References 4 publications

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“…Earlier, Hulse and Tice synthesized MgO nanostructures by directly heating MgO powders at very high temperature of 1850 • C without using any substrate or surfactant [12]. Some latest techniques have been developed to generate MgO nanostructures from the decomposition of some other Mg containing precursors at relatively low temperature of 700-900 • C [13].…”

Section: Introductionmentioning

confidence: 99%

Novel surfactant-free synthesis of MgO nanoflakes

Shah

Qurashi

2009

Journal of Alloys and Compounds

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Section: Introductionmentioning

confidence: 99%

Novel surfactant-free synthesis of MgO nanoflakes

Shah

Qurashi

2009

Journal of Alloys and Compounds

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“…In addition, we discuss the requirements and design of the MgO-core/ semiconductor-shell nanorod system for ultraintense luminescence in other wavelength ranges. Figure 1 a shows the scanning electron microscopy (SEM) images of the MgO-core/TiO 2 -shell nanorods synthesized by the thermal evaporation of Mg 3 N 2 powders at 900 ° C for 1 h in an oxidative atmosphere and the metal organic chemical vapor deposition (MOCVD) of TiO 2 at 350 ° C for 2 h. Recently, MgO 1D nanostructures were synthesized successfully using a range of techniques including sol-gel process; [ 11 ] thermal evaporation of MgO, [ 12 ] MgB 2 , [ 13 ] or Mg 3 N 2 powders; [ 14 ] and pulsed laser deposition. [ 15 ] Of these techniques, the MgO 1D nanostructures with facetted surfaces are known to be grown most easily by the thermal evaporation of Mg 3 N 2 powders.…”

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confidence: 99%

Ultraintense Luminescence in Semiconducting‐Material‐Sheathed MgO Nanorods

et al. 2011

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One-dimensional (1D) nanostructures, such as nanowires, nanorods, nanobelts, nanoribbons, nanoneedles, and nanotubes, have attracted considerable attention due to their unique and fascinating properties as well as their potential technological applications. [ 1 ] In particular, 1D nanostructures are emerging as powerful building blocks for nanoscale photonic devices such as light-emitting diodes, photodiodes, lasers, active waveguides, and integrated electro-optic modulator structures because of their higher luminescence effi ciency. [ 2 , 3 ] The luminescence property of 1D nanostructures can be further enhanced by creating core/shell heterostructures. [4][5][6] Ultraviolet photoluminescence (PL) enhancement by sheathing ZnO 1D nanostructures with a larger bandgap material such as ZnS, [ 7 ] SnO 2 , [ 8 ] MgO, [ 9 ] or Al 2 O 3[ 10 ] has recently been demonstrated. This technique was reported to increase the emission intensity by a few times due to the quantum confi nement effect of the photogenerated carriers in the ZnO cores. [7][8][9][10] In the present paper, we report that sheathing well-faceted MgO nanorods with a semiconductor fi lm with an optimal thickness resulted in ultraintense luminescence characteristic of the sheath material and its origin is discussed. The intensity of the blue-green emission from the MgO-core/TiO 2 -shell nanostructures with a specifi c shell layer thickness ( ≈ 20 nm) was ≈ 220 times higher than that of the original orange emission from the MgO nanorods. In addition, we discuss the requirements and design of the MgO-core/ semiconductor-shell nanorod system for ultraintense luminescence in other wavelength ranges. Figure 1 a shows the scanning electron microscopy (SEM) images of the MgO-core/TiO 2 -shell nanorods synthesized by the thermal evaporation of Mg 3 N 2 powders at 900 ° C for 1 h in an oxidative atmosphere and the metal organic chemical vapor deposition (MOCVD) of TiO 2 at 350 ° C for 2 h. Recently, MgO 1D nanostructures were synthesized successfully using a range of techniques including sol-gel process; [ 11 ] thermal evaporation of MgO, [ 12 ] MgB 2 , [ 13 ] or Mg 3 N 2 powders; [ 14 ] and pulsed laser deposition. [ 15 ] Of these techniques, the MgO 1D nanostructures with facetted surfaces are known to be grown most easily by the thermal evaporation of Mg 3 N 2 powders. Statistical analysis of many SEM images of the core/shell nanorods revealed widths ranging from 60 to 180 nm and lengths ranging from 3 to 5 μ m. The SEM image in Figure 1 b clearly displays the geometrical confi guration of a typical core/shell nanorod with a square cross-section and faceted surfaces. The enlarged SEM image of a typical core/shell nanorod (inset in Figure 1 b) showed that a globular particle did exist at the tip of the nanorod, suggesting that the nanorods were grown via a vapor-liquid-solid mechanism. Five elements including Mg, Ti, O, Cu, and C were detected in the energy dispersive X-ray (EDX) spectra (Figure 1 c) of these core/shell nanorods. Of these elements, Mg, Ti, and O wer...

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“…Different MgO nanostructures have been synthesized by vapor phase precursor method using volatile compounds like MgB 2 [5], Mg 3 N 2 [16,21] and MgCl 3 [8]. Earlier attempts [22,23] at synthesizing MgO nanostructures by directly heating MgO powders required very high temperature (1850 • C) for generating sufficiently high partial pressures of MgO vapor. Yang and Lieber [4] reduced the processing temperature to ∼1200 • C by employing a solid mixture of MgO and graphite as the source of the MgO vapor.…”

Section: Introductionmentioning

confidence: 99%