Novel synthesis of AlN nanowires with controlled diameters

Abstract

A relatively low-cost, high-efficiency method is reported to synthesize AlN nanowires, using carbon nanotubes as templates. The AlN nanowires were fabricated at 1100°C, for 60 min. The diameters of the product could be roughly controlled by the sizes of carbon nanotubes selected as starting materials. The AlN nanowires obtained were among the thinnest ever known. X-ray diffraction, selected-area diffraction, energy dispersive spectroscopy, and high-resolution transmission electron microscopy, etc. were employed to characterize the products, which were found to be single crystals with some defects. The axes of the nanowires are normal to {1010} crystal planes. A new synthesis mechanism is proposed.

Structural, microstructural and magnetic properties of amorphous/nanocrystalline Ni63Fe13Mo4Nb20 powders prepared by mechanical alloying

“…In other words, the agglomerated powders are near-spherical ones with high specific and smooth surfaces without any layeredstructure morphology. This morphology with the disappearance of the contrast feature can be the characteristic of a typical amorphous powder synthesized by MA [12,13]. Fig.…”

“…Using the relationship 1.23 = 2d m sin [25,13,26] (where is the wavelength of the X-radiation used, d m is the distance between the neighboring atoms,  is the peak position and 1.23 is the correction factor used for liquid and amorphous solids), it is possible to determine the distance between the nearest-neighbor atoms from the  values observed. The value of d m or instability factor means the volumetric strain or topological instability.…”

Thermodynamic Modeling of the Undercooled Liquid in the Ni–Zr System

“…29) There are numerous measurements of both latent heats of crystallization from the undercooled liquid. 27,[30][31][32][33][34][35] In the case of the Ni-Zr alloys, it is difficult to measure the glass transition temperature, which it was not detected on the DSC heating curve. 29,36) Altounian et al 34) have pointed out that higher heating rates are required to observe the glass transition because the enthalpy change of the transition is much smaller than that of the crystallization.…”

AlN nanowires: synthesis, physical properties, and nanoelectronics applications

“…Materials such as carbon nanotubes and anodic porous alumina are often used as the templates to confine the formation of AlN nanowire within the nanometer scale. Using carbon nanotubes as templates, Zhu's group and co-workers have successfully synthesized AlN nanowires with controlled diameters at low temperatures [16,31]. These samples were fabricated through the reaction of carbon nanotubes, Al, and Al 2 O 3 in a flowing NH 3 atmosphere.…”

“…Various fabrication methods have been employed to synthesize these nanowires and they may be classified into four main classes: (1) template-confined method [16,[31][32][33], (2) direct current (DC) arc discharge method [34][35][36][37][38], (3) catalyst-assisted vapor-liquid-solid (VLS) growth method [39][40][41][42][43][44][45][46], and (4) catalyst-free vapor-solid (VS) growth method [47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63]. Although significant progress in the synthesis of AlN nanowires has been achieved lately, some challenges remain and are expected to be overcome in the near future.…”