Synthesis of ultra thin α-alumina nanobelts from aluminum powder by chemical vapor deposition

Unique structure and surface-related elastic modulus of alumina nanobelts

“…The structure of the nanobelt determined from the TEM analyses is schematically shown in figure 3 [ ¯] directions, as shown in figure 4. This is well consistent with the previous results obtained in an Ar atmosphere [18,19]. The comparative experiments demonstrate that the reducing atmosphere of high-purity H 2 should be the critical factor for the formation of 2201…”

“…One-dimensional (1D) Al 2 O 3 materials in the form of whiskers, nanowires and nanobelts have excellent mechanical, thermal and optical properties, and thus have been widely used as reinforcing agents, optic fibers and nanoscale sensors [1][2][3][4][5][6]. 1D Al 2 O 3 materials could be fabricated in a large quantity by chemical vapor deposition (CVD) based on vapor-liquid-solid [7][8][9] or vapor-solid mechanisms [10][11][12][13][14][15][16][17][18][19][20], the melt-based method [21] and electrospinning techniques [22]. Usually, Al 2 O 3 nanowires and nanobelts with a nearly defect-free structure can only be synthesized by CVD at high temperatures, but exhibit superior mechanical and optical properties as compared to Al 2 O 3 micron-scale whiskers and bulk single crystals [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26].…”

“…1D Al 2 O 3 materials could be fabricated in a large quantity by chemical vapor deposition (CVD) based on vapor-liquid-solid [7][8][9] or vapor-solid mechanisms [10][11][12][13][14][15][16][17][18][19][20], the melt-based method [21] and electrospinning techniques [22]. Usually, Al 2 O 3 nanowires and nanobelts with a nearly defect-free structure can only be synthesized by CVD at high temperatures, but exhibit superior mechanical and optical properties as compared to Al 2 O 3 micron-scale whiskers and bulk single crystals [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. Depending on the fabrication conditions, the CVD-grown α-Al 2 O 3 nanowires and nanobelts exhibit various sizes, morphologies and structures, such as [0001]-oriented nanowires with hexagonal cross sections [10][11][12][13][14][15], [0001]-oriented nanobelts enclosed by  1010 ( ¯) planes at the upper/lower surfaces [15][16]...…”

“…[ ¯] -oriented nanobelts enclosed by  0001 ( ) planes [18,19]. However, the underlying growth mechanisms for these differences are still not quite clear.…”