| Aluminum nitride is a promising material for structural andfunctional applications. It owns high Direct bandgap, high thermalconductivity, high melting point, high strength, low expansivity, goodchemical stability,etc. Since it has so many excellent properties, thealuminum nitride nanomaterials have already become a focus ofresearch in the field of nanomaterials. Cubic aluminum nitride ownshigher thermal conductivity(250Ｗ ｍ－１. Ｋ－１)and resistivity（>1014Ω m）than the common hexagonal aluminum nitride.And also, Cubicaluminum nitride has the very high hardness（microhardness40005000）.If the technology in the synthesis of cubic aluminum nitride advances, Itwill have great application value for new ceramic materials.In this paper, cubic aluminum nitride were obtained by dc arcplasma method.The XRD, SEM, TEM，EELS mapping techniques are used to characterize the as-synthesized samples. We found that bycontrolling the experimental conditions, the yield of cubic aluminumnitride is different. And the best experiment condition of synthesis ofcubic aluminum nitride is given. Besides, we have studied the highpressure and high temperature behavior of common hexagonalaluminum nitride with our cubic press equipment, we tried to findpossibilities that hexagonal aluminum nitride would have a phasetransition into cubic aluminum nitride.We characterized the as-synthesized samples with X-ray diffractionpatern, Scanning electron microscope and Transmission electronmicroscope etc.At the same time, we have studied the growth mechanism of boronnitride nanotubes and nanocapsules. We synthesize the boron nitridenanostructures with dc arc plasma method. Under the high temperature and high temperature gradient of the device, hexagonal boron nitrideshape into nanotubes and nanocapsules. The X-ray diffraction patern,Scanning electron microscope and Transmission electron microscopetechniques are used to characterize the as-synthesized samples. |
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